This foolproof peanut butter marshmallow fluff fudge — also called fluffernutter fudge — is an easy no-bake treat made with sweetened condensed milk. With roasted peanuts for crunch and just a handful of ingredients, this four-ingredient peanut butter fudge is perfect for anyone who loves peanut butter and marshmallow flavor.
If you love peanut butter, you’ll appreciate how quickly this recipe comes together. It’s fully no-bake, partially made in the microwave (or on a double boiler), and takes only minutes to prepare.
Instead of mixing marshmallow fluff directly into the entire fudge, this version mimics a fluffernutter sandwich: the fluff is swirled on top to give extra marshmallow flavor and a light, pillowy texture.
The squares are soft, slightly chewy, and rich with peanut butter and white chocolate. Roasted peanuts add a welcome crunch that helps balance the sweetness and adds texture to each bite.
Love fluffernutters? Try the stuffed fluffernutter cookies for another crowd-pleasing treat.
Ingredient notes
This no-bake peanut butter fudge requires no corn syrup, powdered sugar, or candy thermometer. It doesn’t need cooked sugar, so you avoid the graininess that sometimes happens with cooked fudge.
What you’ll need:
- White chocolate. Use chopped white chocolate bars when possible — they melt more smoothly and usually taste better. White chocolate chips can work, but they sometimes contain stabilizers that hinder melting.
- Peanut butter. Use creamy, non-natural peanut butter (commercial brands like Jif or similar). Natural, oil-separated peanut butters can affect texture.
- Sweetened condensed milk. One 14 oz can thickens the mixture and helps the fudge set.
- Marshmallow fluff. 6–7 oz of fluff is ideal for swirls and texture on top.
- Toppings. Melted peanut butter for drizzling, roasted peanuts for crunch, and flaky sea salt to finish.
How to make fluffernutter fudge
Line an 8×8″ baking pan with parchment paper, leaving slings on two sides so you can lift the fudge out easily after it sets.
Step 1: In a microwave-safe bowl, heat the white chocolate and peanut butter in 30-second bursts, stirring between each burst until smooth. Alternatively, melt gently over a double boiler.
Step 2: Stir in the sweetened condensed milk until combined. The mixture will thicken as you stir. Transfer the mixture to the prepared pan and press it out toward the edges so it forms an even layer.
Step 3: Dollop marshmallow fluff over the top and use a spatula or a chopstick to swirl it into the peanut butter layer and push toward the edges. The mixture may look messy — the final swirls will transform the appearance.
Step 4: Drizzle a little melted peanut butter over the fluff and use a chopstick or toothpick to create decorative swirls.
Step 5: Scatter roasted peanuts and flaky sea salt across the top. Chill in the refrigerator for about 30 minutes to set.
Step 6: Lift the set fudge from the pan using the parchment slings and cut into 16 squares. Serve at room temperature for the best texture (allow about 30 minutes out of the fridge).
Storing and freezing
Store the fudge tightly covered in the refrigerator for up to one week. For the best flavor and texture, let pieces come to room temperature for about 30 minutes before serving.
To freeze, wrap the cooled fudge tightly in plastic wrap, then foil, and place in a zip-top bag with as much air removed as possible. Freeze up to one month. Thaw fully in the refrigerator or at room temperature until soft before serving.
FAQs
If you used white chocolate chips, they may contain stabilizers that prevent complete melting. If small unmelted bits remain, strain the mixture through a fine-mesh sieve into a clean bowl and continue with the recipe.
This no-bake method should produce a soft, creamy fudge. The pieces can dry slightly as they sit in the fridge over several days, which may lead to a firmer or slightly crumbly texture toward the end of storage.
More peanut butter recipes
- Stuffed Fluffernutter Cookies
- Peanut Butter & Jelly Oat Bars
- Edible Peanut Butter Cookie Dough (with Chocolate Chips)
- Chocolate Peanut Butter Tart
Did you make this recipe? Share your results and leave a star rating — I love to see your photos!
📖Recipe
Peanut Butter Marshmallow Fluff Fudge (Fluffernutter Fudge)
Callan Wenner
Equipment
- 8×8 inch baking pan
- Parchment paper
- Mixing bowls
- Rubber spatula
Ingredients
- 12 oz white chocolate, chopped bars or chips
- 1½ cups creamy peanut butter (about 400 g)
- 14 oz sweetened condensed milk (1 can)
- 6–7 oz marshmallow fluff
- ¼ cup creamy peanut butter, melted, for topping (80 g)
- ⅓ cup roasted, shelled peanuts for topping
- Flaky sea salt, for topping
Instructions
- Line an 8×8 inch pan with parchment paper and set aside.
- In a large microwave-safe bowl, combine the white chocolate and peanut butter. Heat in 30-second bursts, stirring between each, until completely melted and smooth. (Alternatively, melt over a double boiler.)
- Stir in the sweetened condensed milk until combined. The mixture will thicken. Press into the prepared pan and smooth toward the edges.
- Dollop marshmallow fluff over the top and work it into the surface, swirling and pushing to the sides.
- Drizzle the melted peanut butter over the fluff and use a chopstick or toothpick to create swirls.
- Sprinkle roasted peanuts and flaky sea salt across the top.
- Chill in the fridge for about 30 minutes to set. Lift from the pan using the parchment slings and cut into 16 pieces. Serve at room temperature for best texture.
Notes
Store the fudge tightly covered in the fridge for up to one week. Let pieces sit at room temperature about 30 minutes before eating for the best texture.
White chocolate bars melt more reliably than chips. If you must use chips and some pieces do not melt, strain the mixture through a fine mesh sieve to remove chunks.
You can melt the peanut butter and white chocolate over a double boiler if you prefer not to use a microwave.
Carbohydrates: 41 g
Protein: 9 g
Fat: 23 g
Sugar: 35 g
Nutritional information is an estimate per serving.
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