Desserts

Best Peanut Butter Fudge with Marshmallow Fluff: 5 Minutes

I ruined two batches of peanut butter fudge with marshmallow fluff before I figured out that every recipe I’d tried was actually a different method wearing the same name. One boiled sugar to a candy thermometer temperature. Another skipped the stove completely and used condensed milk. No wonder my first attempt turned out grainy and my second never set.

So I stuck with the classic stovetop method here, and I’m walking you through the full stovetop-vs-no-bake comparison, the fluff-vs-creme-vs-regular-marshmallows breakdown, and every fix I’ve found for grainy or gritty fudge that won’t set. Whatever you call it — peanut butter fudge with marshmallow cream, marshmallow fluff peanut butter fudge, pb fudge with marshmallow fluff — this is the method I keep coming back to.

This dessert goes by a lot of different names depending on where you learned it — peanut butter marshmallow fluff, fudge marshmallow fluff, pb fudge with marshmallow creme, peanut butter fudge recipe with marshmallow fluff, peanut butter fudge marshmallow fluff recipe, peanut butter fudge recipe with marshmallow cream, marshmallow fluff peanut butter fudge recipe, peanut butter fudge made with marshmallow fluff, or peanut butter fudge using marshmallow fluff the list goes on.

In my experience they’re all the same method with the same result, the name just changes depending on who taught you. However you landed here, this is genuinely one of the easiest peanut butter fudge recipes with marshmallow fluff I’ve tested, whether you’re making it for the first time or trying to rescue a batch that didn’t set. Some cooks know it as peanut butter fudge marshmallow cream, others as peanut butter marshmallow cream fudge or peanut butter and marshmallow cream fudge — same dessert either way.

No-Bake Option Included • Gluten-Free • 5-Minute Cook Time

Quick Summary

Here’s the short version: I boil sugar and evaporated milk for 3-5 minutes, then stir in marshmallow fluff and peanut butter off the heat. Below you’ll get my full stovetop vs. no-bake comparison, a fluff vs. creme vs. regular marshmallows guide, and the troubleshooting I wish I’d had for grainy fudge or fudge that won’t set. I’ve also included a no-bake condensed-milk version for anyone who’d rather skip the stove entirely, and if you like your desserts fuss-free, my coconut cookies are the same kind of low-effort, high-payoff treat.

Recipe Snapshot

Prep TimeCook TimeYieldsCaloriesCourse
10 minutes5 minutes36 pieces108 per pieceDessert

Ingredients

  • 2 cups granulated sugar
  • 2/3 cup evaporated milk (not sweetened condensed milk)
  • 1/4 teaspoon salt
  • 7 tablespoons butter
  • 1 (7-ounce) jar marshmallow fluff (see comparison below)
  • 1 1/2 cups creamy peanut butter (not natural-style)
  • 1 teaspoon vanilla extract
Ingredients for peanut butter fudge with marshmallow fluff laid out on a counter, including a jar of marshmallow fluff, peanut butter, sugar, and evaporated milk, no text or branding


Tools You’ll Need

  • Heavy-bottomed 3-quart saucepan
  • 8×8-inch baking pan
  • Parchment paper
  • Wooden spoon
  • Candy thermometer (optional, see doneness guide below)


Marshmallow Fluff vs. Marshmallow Creme vs. Regular Marshmallows

This is the part I get asked about most, and honestly it confused me too at first — the terms get thrown around interchangeably even though they behave completely differently in fudge:

ProductWhat It IsWorks in This Recipe?
Marshmallow FluffA specific brand-name spreadable marshmallow product, sold in jarsYes — this recipe
Marshmallow CremeThe generic term for the same style of product (Jet-Puffed, store brands)Yes — identical use
Regular MarshmallowsWhole or mini marshmallows, coated in cornstarch to prevent stickingNot recommended — the cornstarch coating dries out the fudge

If marshmallow fluff genuinely isn’t available where you live, regular marshmallows can work in a pinch — measure 7 ounces by weight rather than by cup, since they pack differently than fluff. I learned that the hard way the first time I eyeballed it by cup and ended up with a batch that never set right.

How to Make Peanut Butter Fudge with Marshmallow Fluff, Step by Step

Here’s exactly how I put it together, nothing fancy, just don’t walk away once the sugar starts boiling.1. Line an 8×8-inch baking pan with parchment paper, leaving overhang on two sides for easy removal. I always leave the overhang, it’s the difference between lifting the whole block out clean and fighting it out of the pan in pieces.

2. In a heavy-bottomed saucepan, melt the butter over medium heat. Swirl it up the sides of the pan to grease the edges.

3. Pour in the evaporated milk, then slowly add the sugar and salt to the center of the pan. Stir until fully dissolved — rub a bit between your fingers to check for grit before moving on.

Sugar and evaporated milk boiling in a saucepan on the stove, no text or branding

4. Bring the mixture to a full rolling boil over medium-high heat, stirring constantly. Boil for 3-5 minutes (see the doneness guide below for exact timing).

5. Remove from heat. Working quickly, stir in the marshmallow fluff and peanut butter until smooth, then add the vanilla extract.

Marshmallow fluff and peanut butter being stirred into the boiled sugar mixture in a saucepan, no text or branding

6. Immediately pour the fudge into the prepared pan and smooth into an even layer. Don’t scrape the sides of the pot into the pan — any dried bits will make the top grainy.

It should pour thick and glossy, almost like warm caramel — if it’s already clumping in the pot before you tip the pan, you let it go a beat too long.

Peanut butter fudge with marshmallow fluff being poured into a parchment-lined baking pan, no text or branding

7. Let the fudge cool at room temperature for at least 2 hours, until fully set.

8. Lift the fudge out using the parchment overhang, then slice into 1-inch squares.

How Do You Know When the Fudge Is Done Boiling?

This is the step that trips up most first-time fudge makers, and different recipes test for it in genuinely different ways:

MethodHow It WorksBest For
Candy thermometerBoil until the mixture reads 234-236°F (soft-ball stage)Most accurate, no guesswork
Ice-water soft-ball testDrop a bit of the boiling mixture into ice water; it should form a soft, pliable ballNo thermometer needed, slightly more practice required
Timed boil (this recipe)Boil at a full rolling boil for exactly 3-5 minutes, stirring constantlySimplest for beginners, works reliably with a heavy pan

Any of the three methods works. If you have a candy thermometer, use it — it removes almost all the guesswork from peanut butter fudge with marshmallow fluff and is the most foolproof option for a first attempt. The soft-ball stage (234-236°F) is the same temperature range candy-making science has used for generations to identify when sugar syrup is ready for fudge, pralines, and fondant.

Stovetop vs. No-Bake: Which Method Should You Use?

I made this mistake myself early on — I searched for peanut butter fudge with marshmallow fluff online and assumed every result was the same recipe. It’s not. Here’s how the two methods actually compare:

MethodKey IngredientsTextureEffort
Stovetop boiled (this recipe)Sugar, evaporated milk, fluff, peanut butterClassic fudge texture — dense, smooth, slightly crumblyMedium — requires boiling and timing
No-bakeCondensed milk, white chocolate, fluff, peanut butterSofter, creamier, more like a set ganacheLow — no stovetop cooking, microwave only

Neither version is more correct than the other — they’re just different textures wearing the same name. See the No-Bake Version in the variations section below for the full method.

Why Is My Peanut Butter Fudge Grainy or Won’t Set?

These are the two most common complaints with this style of fudge:

  • Grainy or gritty texture: Almost always means the sugar wasn’t fully dissolved before the mixture came to a boil, or the fudge boiled too long and started to crystallize. Always check for grit between your fingers before increasing the heat, and stick to the timing in the doneness guide above.
  • Fudge that stays soft or goopy: Usually means the sugar mixture didn’t boil long enough to reach the right stage. Unfortunately, this isn’t fixable after the fact — a brief fridge chill will firm it up temporarily, but it will turn sticky again at room temperature. The real fix is remaking the batch and boiling for the full time in the doneness guide above, or using a candy thermometer to confirm it actually hits 234-236°F next time.
  • Dry, crumbly fudge: Usually caused by overcooking the sugar mixture past the right stage, or using a thin pan that creates hot spots and scalds the mixture unevenly. A heavy-bottomed pan makes a real difference here.


Variations to Try

No-Bake Peanut Butter Fudge with Marshmallow Fluff

For a completely no-bake peanut butter fudge with fluff, melt 12 ounces of white chocolate with 1 1/2 cups peanut butter in the microwave in 30-second bursts. Stir in one 14-ounce can of sweetened condensed milk until thick, then swirl in the marshmallow fluff on top rather than mixing it in fully. Chill in the refrigerator for 30 minutes before slicing.

. No-bake peanut butter fudge with marshmallow fluff swirled with white chocolate, overhead shot, no text or branding


Microwave Peanut Butter Fudge

For microwave peanut butter fudge with marshmallow fluff, combine the sugar, evaporated milk, and butter in a microwave-safe bowl and cook on high in 2-minute bursts, stirring between each, until the mixture reaches a full boil for a total of about 4 minutes. Remove and stir in the fluff, peanut butter, and vanilla as usual.

Chocolate Peanut Butter Fudge

For chocolate peanut butter fudge with marshmallow fluff, stir in 1 cup of semi-sweet chocolate chips along with the peanut butter, or swirl 1/2 cup melted chocolate over the top just before the fudge sets for a marbled look.

3-Ingredient Marshmallow Fluff Peanut Butter Fudge

For a genuinely simple 3 ingredient marshmallow fluff peanut butter fudge, skip the stovetop step entirely: microwave 1 1/2 cups peanut butter chips with 1 cup peanut butter until smooth, then fold in the full jar of marshmallow fluff. Spread into a lined pan and chill until firm.

Common Mistakes to Avoid

  • Using sweetened condensed milk instead of evaporated milk in the stovetop version — they are not interchangeable and will change the result completely.
  • Using natural-style peanut butter — the oil separation prevents the fudge from setting properly.
  • Walking away during the boil — this fudge moves fast, and unattended sugar can scorch or crystallize in seconds.
  • Refrigerating the finished stovetop fudge — cold, dry air makes it crumbly. Store it at room temperature instead (see Storage below).


What to Serve With Peanut Butter Fudge

  • A cold glass of milk, for dunking
  • Alongside other candies on a holiday gift plate
  • Crumbled over vanilla ice cream
  • Packed in an airtight tin as a homemade gift

If you’re already on a roll with easy stovetop sweets, my sugar cookies are just as forgiving — same weeknight energy, different shape entirely.

Overhead shot of sliced peanut butter fudge squares stacked on parchment paper, no text or branding


Storage

I keep mine at room temperature, tightly wrapped or in an airtight container, and it’s still good two weeks later, the sugar content does the preserving for you. Don’t refrigerate the stovetop version, cold air dries it out and makes it crumbly, which I found out the annoying way. To freeze it, wrap the whole block (not individual pieces) tightly in plastic wrap, then foil, and it’ll keep for up to 3 months. Thaw at room temperature before slicing.

Cut into it while it’s still glossy on top and just barely set — the edges should hold a clean, sharp line. That’s the tell it’s ready.

Nutrition (per piece)

NutrientAmount
Calories108 kcal
Carbohydrates12g
Protein2g
Fat6g
Saturated Fat2g
Sugar10g

Nutrition values are estimates and will vary based on exact ingredients and slice size.

Frequently Asked Questions

Can I use marshmallows instead of marshmallow fluff?

Yes, though it’s not ideal — regular marshmallows are coated in cornstarch, which can slightly dry out the finished fudge. See the Fluff vs. Creme vs. Regular Marshmallows table above for the details.

Why did my peanut butter and marshmallow fluff fudge turn out grainy?

In my experience it’s almost always undissolved sugar. Make sure every granule has dissolved before the mixture hits a boil, and don’t let crystals sit on the sides of the pan.

Can I make this peanut butter fudge with marshmallow creme instead of fluff?

Yes — marshmallow fluff and marshmallow creme are essentially the same product under different regional names, and either works identically in this recipe.

How long does peanut butter fudge with marshmallow fluff last?

Up to 2 weeks at room temperature in an airtight container. See the Storage section above for freezing instructions if you want it to last longer.

Do I need a candy thermometer to make this fudge?

No — a candy thermometer makes it more foolproof, but the timed-boil method in this recipe works reliably without one. See the doneness guide above for all three testing options.

Related Recipes

Peanut butter fudge with marshmallow fluff squares stacked on parchment paper, smooth golden-tan color
Jonas Mitchell

Peanut Butter Fudge with Marshmallow Fluff

Rich, creamy stovetop peanut butter fudge made with marshmallow fluff — ready in about 10 minutes of prep and 5 minutes of cooking.
Prep Time 10 minutes
Cook Time 5 minutes
Cooling Time 2 hours
Total Time 2 hours 15 minutes
Servings: 36 pieces
Course: Dessert
Cuisine: American
Calories: 108

Ingredients
  

  • 2 cups granulated sugar
  • 2/3 cups evaporated milk (not sweetened condensed milk)
  • 1/4 teaspoon salt
  • 7 tablespoons butter
  • 1 (7-ounce) jar marshmallow fluff
  • 1 1/2 cups creamy peanut butter (not natural-style)
  • 1 teaspoon vanilla extract

Equipment

  • 1 heavy-bottomed 3-quart saucepan
  • 1 8×8-inch baking pan
  • 1 roll parchment paper
  • 1 wooden spoon
  • 1 candy thermometer (optional)

Method
 

  1. Line an 8×8-inch pan with parchment paper.
  2. Melt butter in a heavy saucepan over medium heat, greasing the sides.
  3. Add evaporated milk, then sugar and salt. Stir until fully dissolved.
  4. Bring to a full rolling boil, stirring constantly, for 3-5 minutes.
  5. Remove from heat. Stir in marshmallow fluff, peanut butter, and vanilla until smooth.
  6. Pour immediately into the prepared pan and smooth into an even layer.
  7. Cool at room temperature for at least 2 hours until fully set.
  8. Lift out using the parchment overhang and slice into 1-inch squares.

Notes

Do not use sweetened condensed milk or natural-style peanut butter. Store at room temperature, never in the fridge — cold air makes it crumbly.
Nutrition (per piece)  Calories 108 | Carbs 12g | Protein 2g | Fat 6g | Saturated Fat 2g | Sugar 10g

This recipe is intended for general home cooking guidance. Boiling sugar reaches extremely high temperatures — use caution, keep children away from the stove during this step, and never leave the mixture unattended while it boils.

Jonas Mitchell has a sweet tooth that shows up a lot in his RecipeValley dessert recipes, fudge especially. He holds no clinical nutrition credential, so this is kitchen-tested guidance, not medical advice.

Jonas Mitchell

Jonas Mitchell is a recipe developer at RecipeValley, focused on approachable, kitchen-tested recipes and everyday cooking. He does not hold a clinical nutrition credential, and his content is for informational purposes only and is not a substitute for advice from a doctor or registered dietitian.

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