Sweet and salty marshmallow-peanut butter bliss! These Fluffernutter Cookies pair two soft, chewy peanut butter cookies with a cloud of marshmallow frosting. 
I was 14 the first time I heard about a fluffernutter sandwich. Growing up in Canada, I hadn’t encountered them at home, so when we visited Washington, DC I was surprised to see one of the menu items labeled a fluffernutter. We laughed at the odd idea — peanut butter and marshmallow on bread — but the combination sounded both ridiculous and irresistible.
That salty-sweet contrast stuck with me. Peanut butter’s rich, savory flavor combined with pillowy marshmallow creates the kind of treat you don’t overthink — you just enjoy. So I turned that sandwich into dessert and made Fluffernutter Cookies.
Why These Fluffernutter Cookies Are So Good
These are two super-soft, chewy peanut butter cookies sandwiched with a fluffy marshmallow frosting. The cookies are full of peanut butter flavor, and the frosting tastes like marshmallow without becoming an overly sticky mess. Sandwich cookies also mean more frosting in every bite — double the pleasure with minimal fuss.
The cookie base follows a classic approach: dry ingredients like flour, cornstarch (for tenderness), baking soda and salt get sifted together. The butter and sugars are creamed until light, then peanut butter, eggs and vanilla are added. Finally, the flour mixture is folded in gently. No dough chilling is required for this recipe, but avoid flattening the dough before baking so the cookies remain thick and chewy. A cookie scoop helps produce uniformly sized rounds perfect for sandwiching.
The marshmallow frosting is straightforward: beat softened butter with powdered sugar, then mix in a jar of marshmallow cream until the frosting is light and fluffy. If it’s a touch too thick, one tablespoon of milk or cream will loosen it to a spreadable texture.
Ingredients
For the Peanut Butter Cookies
- 2 and 3/4 cups all-purpose flour, spooned and leveled
- 1 tablespoon cornstarch
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup (2 sticks) unsalted butter, softened to room temperature
- 1 cup granulated sugar
- 1 cup brown sugar, lightly packed
- 1 cup peanut butter (not natural or whipped)
- 2 large eggs
- 2 teaspoons vanilla extract
- 1/4 cup chopped peanuts, optional
For the Marshmallow Frosting
- 1 cup unsalted butter, softened
- 2 cups powdered sugar, sifted
- 1 (7 oz) jar marshmallow cream
- 1 tablespoon milk or cream, if needed
Makes: 24 cookies
Prep: 30 mins | Cook: 8 mins | Total: 1 hr 30 mins
Instructions
Peanut Butter Cookies
- Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper or silicone mats.
- Sift together the flour, cornstarch, baking soda and salt in a large bowl.
- In a separate large bowl, beat the butter and both sugars until light and fluffy. Add the peanut butter, eggs and vanilla and beat until combined.
- With the mixer on low speed, gradually mix in the flour mixture until just combined.
- Form the dough into balls about 1 tablespoon in size and place them at least 2 inches apart on the prepared baking sheets. If desired, press a few chopped peanuts on top of each cookie for texture.
- Bake 8–10 minutes, until the tops look just set. Allow the cookies to cool completely on a wire rack.
Marshmallow Frosting and Assembly
- In a large bowl, beat the softened butter until smooth. Slowly add the sifted powdered sugar on low speed until incorporated.
- With the mixer on medium speed, beat in the marshmallow cream until the frosting is light and fluffy. If the frosting seems too thick, add 1 tablespoon of milk or cream and beat again until spreadable.
- Spread marshmallow frosting on the bottom of one cookie and sandwich with a second cookie. Repeat with remaining cookies.
These Fluffernutter Cookies are ideal for anyone who loves peanut butter and the irresistible pairing of salty and sweet. They make a perfect treat for snack time, bake sales, or any time you crave a nostalgic, comforting dessert.
Nutrition
Calories (per cookie, approximate): 385 kcal