Chewy Fluffernutter Peanut Butter & Marshmallow Cookies

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Why I Love These Fluffernutter Cookies

1. Incredible flavor: The creamy peanut butter paired with gooey marshmallow fluff delivers the perfect balance of sweet and salty.
2. Soft & chewy texture: Slightly underbake for tender centers — they firm up as they cool.
3. One-bowl recipe: For how impressive they look, these cookies are fast and simple. The marshmallow step is the only slightly fiddly part, but it’s worth it.

Ingredient Notes & Substitutions

• Unsalted butter: Use real butter. Margarine makes the dough too soft and prevents the marshmallow from working properly. If you use salted butter, reduce or omit added salt.
• Creamy peanut butter: Choose creamy (not natural) for the right consistency and texture.
• Marshmallow fluff: A 7-ounce jar is sufficient. Fluff melts into a smooth, gooey center; mini marshmallows will dissolve or alter the texture and appearance.

Step 1: Make Dough

1. Preheat the oven to 350°F (175°C).
2. In a large microwave-safe bowl, melt ½ cup (1 stick) unsalted butter for 45–60 seconds. Cover with a paper towel to prevent splattering.
3. Add ½ cup light brown sugar and ½ cup granulated sugar; stir until combined.
4. Mix in 1 large egg plus 1 extra yolk and 2 teaspoons vanilla extract. Stir in ½ cup creamy peanut butter.
5. Add ½ teaspoon baking soda, ½ teaspoon baking powder, and ½ teaspoon salt; mix to combine.
6. Stir in 1¼ cups all-purpose flour until no dry streaks remain.
7. Let the dough rest 5 minutes to firm up. If it’s still too sticky to shape, chill 5–10 minutes in the fridge.

Step 2: Roll & Add Marshmallow Fluff

1. Line a baking sheet with parchment paper. Portion dough into 4-tablespoon-sized scoops.
2. Roll each scoop into a ball, press a larger crater in the center, add about 1 tablespoon marshmallow fluff, then cover and reshape into a smooth ball.

Step 3: Bake

1. Bake at 350°F for 10–11 minutes, or until the edges are lightly golden. For soft and chewy cookies, remove them before the edges brown — centers will set as they cool.
2. Remove from the oven and place the entire pan on a cooling rack. Sprinkle flaky sea salt on top, if desired.

Tips & Variations

• Cool on the pan: Let cookies cool on the hot pan for 15–30 minutes so they finish baking and set. Eating too soon can leave centers doughy.
• Add mix-ins: Fold in chocolate chips or chopped peanuts for extra texture and flavor.
• Ice cream sandwiches: Omit the marshmallow fluff to use these cookies for ice cream sandwiches.

Storage & Freezing

• Storage: These cookies are best within 2–3 days; they may dry out slightly because of the melted butter. Store in an airtight container or a resealable bag.
• Freezing: Freezing is not recommended—marshmallow fluff can become sticky and change texture after thawing.

Frequently Asked Questions