Peanut Butter Marshmallow Cookies — Soft, Gooey & Ready in 30 Minutes

You know that moment when you bite into something and your brain just goes completely quiet? That's exactly what these peanut butter marshmallow cookies do.

They're soft, chewy, packed with that deep nutty peanut butter flavor, and then — boom — a pocket of gooey, toasted marshmallow hits you out of nowhere. It's the kind of cookie that makes you pause mid-bite and say "okay, this is it."

I stumbled onto this recipe on a rainy Wednesday afternoon when I wanted something comforting but didn't feel like spending an hour in the kitchen. The result was better than I expected — and trust me, I've made some questionable cookie experiments in the past. These ones? A total win.

The best part is that you probably already have everything you need sitting in your pantry right now. No fancy equipment, no complicated techniques. Just simple ingredients, one bowl, and about 30 minutes standing between you and cookie heaven. Let's get into it.

Why you'll love this recipe

• Ready in 30 minutes. From cold butter to warm cookies in half an hour. Perfect for when the craving hits and patience is running low.
• One bowl, minimal mess. Because nobody wants to spend more time washing dishes than eating cookies. FYI — less cleanup equals more happiness.
• That gooey marshmallow center. Every bite has a little surprise pocket of melted, toasty marshmallow. It's basically a campfire s'more in cookie form.
• Kid and family approved. These disappear fast whenever I make them for family. Like, suspiciously fast.
• Pantry staple ingredients. No obscure ingredients, no special trips to a fancy grocery store. Everything here is straightforward and easy to find.
• Easily customizable. Want to add chocolate chips? Go for it. Prefer crunchy peanut butter over smooth? Absolutely do it. This recipe is very forgiving.

Ingredients with key notes

The main ingredients

• 1 cup creamy peanut butter — Use a regular commercial peanut butter like Jif or Skippy for the best texture. Natural peanut butter tends to make the dough too oily and can affect how the cookies hold together.
• 1/2 cup unsalted butter, softened — Room temperature is important here. Cold butter won't cream properly and you'll end up with a lumpy dough. If you forgot to take it out, microwave it in 5-second bursts.
• 3/4 cup granulated sugar — Gives the cookies that slightly crisp edge while keeping the center soft.
• 1/2 cup brown sugar, packed — This is where the chewy texture and that hint of molasses flavor come from. Don't skip it.
• 2 large eggs — Room temperature eggs blend into the dough more evenly. Cold eggs can cause the butter to seize up.
• 1 tsp vanilla extract — Pure vanilla, not imitation. It makes a difference, IMO.
• 1 1/2 cups all-purpose flour — Spoon the flour into the measuring cup and level it off. Scooping directly packs in too much flour and makes dry, dense cookies.
• 1 tsp baking soda — Helps the cookies puff up and spread just right.
• 1/2 tsp salt — Balances the sweetness and brings out the peanut butter flavor. Don't skip this one.
• 1 1/2 cups mini marshmallows — Mini marshmallows melt better and distribute more evenly throughout the cookies. Regular-sized ones tend to create big air pockets.

Optional add-ins

• 1/2 cup chocolate chips (highly recommended — peanut butter and chocolate is never a bad idea)
• 1/4 cup chopped roasted peanuts for extra crunch
• A sprinkle of flaky sea salt on top before baking

Step-by-step instructions

Step 1 — Preheat and prep

Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper. This step is non-negotiable — parchment paper prevents sticking and makes cleanup about 100 times easier. Set aside.

Step 2 — Cream the butter and sugars

In a large mixing bowl, beat together the softened butter, peanut butter, granulated sugar, and brown sugar until the mixture is light and fluffy. This takes about 2–3 minutes with a hand mixer on medium speed. If you're going by hand, just mix vigorously until you don't see any lumps. The fluffier the better here — this step is what gives the cookies that soft, tender texture.

Step 3 — Add the eggs and vanilla

Add the eggs one at a time, beating well after each addition. Then add the vanilla extract and mix until everything is fully combined. The dough should look smooth and glossy at this point.

Step 4 — Mix in the dry ingredients

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients into the wet mixture, stirring until just combined. Don't overmix — once you can't see flour streaks, stop. Overmixing develops gluten and makes the cookies tough instead of tender.

Step 5 — Fold in the marshmallows

Gently fold in the mini marshmallows (and chocolate chips if you're using them). Work quickly here — you want the marshmallows evenly distributed but you don't want to work the dough too much. The dough will be a little sticky. That's totally normal.

Step 6 — Scoop and bake

Using a cookie scoop or a tablespoon, drop rounded balls of dough onto the prepared baking sheets, spacing them about 2 inches apart. The cookies will spread during baking, so give them room. Bake for 12–14 minutes, or until the edges are set and just starting to turn golden. The centers will look slightly underdone — that's exactly what you want.

Step 7 — Cool (if you can wait)

Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack. They firm up as they cool. Eat one warm though, seriously — that gooey marshmallow straight out of the oven is an experience you owe yourself.

Serving suggestions

• With a cold glass of milk. Classic for a reason. The cold milk against the warm, gooey cookie is genuinely one of life's simple pleasures.
• As a dessert platter. Stack them on a board with some chocolate-dipped strawberries and brownies for a crowd-pleasing spread at gatherings.
• Cookie ice cream sandwiches. Wait for the cookies to cool completely, then sandwich a scoop of vanilla ice cream between two of them. You're welcome.
• Crumbled over vanilla ice cream. Break them up and use as a topping. It's essentially a deconstructed cookie sundae and nobody is complaining.
• As an after-school snack. Kids go absolutely crazy for these. Pair with fruit to balance things out.

Storage tips

At room temperature

Store the cookies in an airtight container at room temperature for up to 5 days. Place a slice of bread in the container — it sounds odd but it keeps the cookies soft by absorbing excess moisture.

In the refrigerator

You can refrigerate them for up to 1 week, though the marshmallows can get a little firmer when cold. Let them come back to room temperature before eating or warm them in the microwave for 10–15 seconds.

Freezing

These cookies freeze beautifully. Store in a freezer-safe bag or container for up to 3 months. You can also freeze the raw cookie dough balls on a baking sheet, then transfer them to a bag and bake straight from frozen — just add 2–3 extra minutes to the baking time.

A quick word before you go

These peanut butter marshmallow cookies have become one of those recipes I come back to again and again — not because they're complicated or impressive in a showy way, but because they're just genuinely good. Simple, comforting, and made with ingredients you actually have. That's the kind of cooking I'm here for.

If you make these, I'd love to hear how they turned out. Drop a comment below or tag me on Pinterest. And if you've got your own spin on them — different add-ins, a twist on the flavors — I'm always curious to hear what you come up with. Now go make some cookies. :)

— Kip