Soft and Gooey Peanut Butter Marshmallow Cookies
These peanut butter marshmallow cookies have crisp edges, chewy centers, and glossy ribbons of caramelized marshmallow woven right through.
They come together fast in one bowl and bake in about 12 minutes, so they’re easy to slide into a weeknight baking mood.
What Makes These Cookies So Good
The peanut butter flavor is deep and salty, not just sweet. I use a mix of brown and white sugar so the cookies spread just enough without going flat, and the brown sugar adds a hint of toffee that plays off the peanut butter.
The mini marshmallows don’t disappear into the dough; they melt into chewy, golden pockets that stay soft even after the cookies cool. This is the version I keep coming back to when I want a cookie that feels a little more fun than a plain peanut butter cookie.
Ingredients
- 1/2 cup unsalted butter, softened: brings structure and richness; keep it cool room temp, not greasy.
- 1/2 cup creamy peanut butter: use conventional peanut butter like Jif or Skippy for the best texture.
- 1/2 cup packed brown sugar: adds moisture and a toffee note.
- 1/4 cup granulated sugar: balances the spread and keeps the edges crisp.
- 1 large egg: binds the dough; let it come to room temperature.
- 1 teaspoon vanilla extract: rounds out the peanut flavor.
- 1 1/4 cups all-purpose flour: spoon and level for an accurate measure.
- 1/2 teaspoon baking soda: gives the cookies a gentle lift.
- 1/4 teaspoon salt: cuts the sweetness and emphasizes the peanut butter.
- 1 cup mini marshmallows: these melt into little pockets without disappearing entirely; don’t use large marshmallows.
Variations / Substitutions
- Crunchy peanut butter: swap in the same amount for added texture; the cookies will have little peanut bits throughout.
- Chocolate chips: fold in 1/2 cup semisweet chips along with the marshmallows for a peanut butter cup vibe.
- Dairy-free: use a plant-based butter stick and replace the egg with a flax egg (1 tablespoon ground flax + 2.5 tablespoons water).
- Gluten-free: use a 1:1 gluten-free all-purpose flour blend; the dough may be slightly softer, so chill it for 20 minutes before baking.
Stuffed Chocolate Chip Cookies are next on our list if these cookies are your kind of dessert.
How to Make Peanut Butter Marshmallow Cookies
Step 1: Cream the Peanut Butter Mixture
Preheat your oven to 350°F (180°C) and line two baking sheets with parchment paper. In a large bowl, beat the 1/2 cup softened butter, 1/2 cup peanut butter, 1/2 cup brown sugar, and 1/4 cup granulated sugar with a hand mixer on medium speed until the mixture turns pale, fluffy, and almost the texture of thick frosting, about 2 minutes.
Stop once the sugar is fully incorporated and the whole thing looks smooth and airy, not grainy. If the butter was properly softened, it will come together without any resistance.
Step 2: Fold in the Dry Ingredients
Add the 1 1/4 cups flour, 1/2 teaspoon baking soda, and 1/4 teaspoon salt directly into the bowl. Mix on low speed just until the flour disappears, or fold it in by hand with a sturdy spatula to avoid overworking the dough.
The dough will be soft, a little sticky, and pull away from the sides of the bowl in a solid mass. A few faint streaks of flour here and there are fine; they will disappear once the marshmallows go in.
Step 3: Stir in the Marshmallows
Pour in the 1 cup mini marshmallows and fold them through the dough using a spatula. Work gently so you don’t smash the marshmallows into paste.
You want most of them intact, with a few peeking out of the dough balls later. The dough will look bumpy and uneven at this stage, and that’s exactly how it should look before scooping.
Step 4: Scoop and Bake
Scoop rounded tablespoon amounts of dough onto the prepared baking sheets, spacing them about 2 inches apart. Slide the sheets into the oven and bake for 10 to 12 minutes, until the edges turn light golden and the tops look set but still soft in the very center.
The marshmallows on the surface will caramelize into shiny, amber ribbons. The centers will feel underdone when you pull the trays out, but they firm up as the cookies cool.
Step 5: Cool and Serve
Let the cookies rest on the baking sheets for 5 minutes, then transfer them to a wire rack to finish cooling. Use a thin spatula to lift them carefully; the melted marshmallow can be a little sticky.
Serve them warm if you can, while the marshmallow pockets are still gooey, or let them cool completely. Even at room temperature, the caramelized bits stay soft and chewy for days.
A Few Tips Before You Bake
- Use mini marshmallows: large ones melt into puddles instead of staying as ribbons. If all you have are large marshmallows, chop them into small pea-sized pieces.
- For a salty-sweet edge, sprinkle a few flakes of flaky sea salt on top of the cookies the moment they come out of the oven. It brightens the peanut butter and caramel notes.
- Chill the dough if it feels too soft: a warm kitchen can make the dough greasy and cause excessive spreading. Pop the bowl in the fridge for 15 minutes before scooping.
- Let the trays cool between batches: reusing a hot baking sheet can make the dough start to spread too soon and flatten before it sets. A quick rinse under cold water and a dry works if you’re in a hurry.
Storing Leftovers
Refrigerate: Keep baked cookies in an airtight container at room temperature for up to 3 days. To extend freshness, store them in the fridge for up to a week. Let them come to room temp or warm briefly before eating.
Reheating: Microwave individual cookies for 10 seconds to resoften the marshmallow, or place a few on a baking sheet in a 300°F oven for 3 to 4 minutes.
Frequently Asked Questions
Can I use natural peanut butter?
Natural peanut butter makes the dough more crumbly and oily. If that’s what you have, add 1 to 2 tablespoons of milk to bring the dough together, then chill it for 20 minutes before baking.
Can I use almond butter instead?
Yes, but the dough will be a bit drier. Add 1 tablespoon of milk and expect a more crumbly texture. The cookies will spread a little less and have a nuttier, less sweet flavor.
Can I freeze the cookie dough?
Scoop the dough into balls, place them on a tray, and freeze until solid. Transfer to a zip-top bag and freeze for up to 2 months. Bake from frozen, adding 1 to 2 minutes to the time.
Why didn’t my cookies spread?
Too much flour or an overly chilled dough can prevent spreading. Make sure you spoon the flour into your measuring cup and level it off rather than scooping directly from the bag. Let the dough sit at room temperature for a few minutes before scooping if it feels very cold.
Peanut Butter Marshmallow Cookies Recipe
Ingredients
Method
- Preheat oven to 350°F (180°C) and line two baking sheets with parchment. Beat butter, peanut butter, brown sugar, and granulated sugar until pale and fluffy, about 2 minutes.
- Mix in the egg and vanilla until combined.
- Fold in flour, baking soda, and salt on low speed just until no dry streaks remain.
- Gently stir in the mini marshmallows.
- Scoop tablespoon-sized mounds onto the prepared sheets, 2 inches apart. Bake for 10 to 12 minutes, until edges are golden and centers look slightly underdone.
- Cool on the sheets for 5 minutes, then transfer to a wire rack to cool completely.
Notes
