Name: Reese's Marshmallow Brownies
Prep time: 10 min
Cook time: 30 min
Total time: 1 h 15 min
Cuisine: American
Ingredients: 1 box brownie mix (plus ingredients listed on the box – typically eggs, oil, and water) or homemade brownie batter; 3 cups mini marshmallows; 1/2 cup creamy peanut butter; 1 cup semisweet chocolate chips; 2 tbsp butter; 1/2 tsp vanilla extract (optional); 1 cup chopped Reese’s Peanut Butter Cups (mini or regular size)

These Reese’s Marshmallow Brownies are the ultimate dessert indulgence. I layer rich, fudgy brownies with gooey marshmallows and a smooth, peanut butter-chocolate topping loaded with chopped Reese’s. Every bite is a dreamy mix of textures and flavors that satisfies my sweet tooth completely.

Why You’ll Love This Recipe

I love how these brownies bring together everything I crave—chocolate, marshmallow, and peanut butter—in one decadent bar. They’re easy to make with simple ingredients and always a hit at parties, bake sales, or just a casual night in. The layers are gooey, rich, and filled with Reese’s candy for the perfect chocolate-peanut butter combo.

ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

Brownie mix (plus ingredients listed on the box – usually eggs, oil, and water) or homemade brownie batter
Mini marshmallows
Creamy peanut butter
Semisweet chocolate chips
Butter
Vanilla extract (optional)
Chopped Reese’s Peanut Butter Cups (mini or regular size)

directions

I preheat the oven to 350°F and line a 9×13-inch baking dish with parchment paper or lightly grease it.
I prepare the brownie batter according to the package directions or use my favorite homemade recipe.
I pour the batter into the prepared pan and bake according to the instructions, usually around 25–30 minutes, until a toothpick comes out mostly clean.
I remove the brownies from the oven and immediately sprinkle mini marshmallows evenly over the top.
I return the pan to the oven for 2–3 minutes, just until the marshmallows puff up—then I take it out and let it cool slightly.
In a small saucepan or microwave-safe bowl, I melt the peanut butter, chocolate chips, and butter together until smooth. I stir in vanilla if using.
I pour the peanut butter-chocolate mixture over the marshmallows and spread it gently to cover the top.
I sprinkle chopped Reese’s over the topping while it’s still warm, then let the brownies cool completely (or chill them to set faster).
Once set, I slice into bars and serve.

Servings and timing

This recipe makes about 20 to 24 brownies. It takes 10 minutes to prep, 30 minutes to bake, and another 30–45 minutes to cool and set—so I usually have them ready in about 1 hour and 15 minutes.

Variations

I sometimes add crushed pretzels or chopped peanuts on top for extra crunch. For an even richer flavor, I use dark chocolate chips in the topping. If I want extra peanut butter flavor, I swirl some into the brownie batter before baking. I’ve also made a version with marshmallow fluff instead of mini marshmallows for an ultra-gooey texture.

storage/reheating

I store these brownies in an airtight container at room temperature for up to 3 days or in the fridge for up to 5 days. For longer storage, I freeze them in layers with parchment paper in between. To serve, I let them come to room temperature or microwave a slice for a few seconds if I want it warm and gooey.

FAQs

Can I use homemade brownie batter?

Yes, I often do. Any rich, fudgy brownie recipe works great as the base.

Do the marshmallows stay soft after cooling?

They set up a bit as the bars cool but still stay chewy and gooey in the center.

Can I make this without peanut butter?

If I skip the peanut butter, I just melt the chocolate and butter together and use chopped candy or nuts on top. Sunflower seed butter also works for a peanut-free version.

How do I keep the chocolate topping smooth?

I melt the topping slowly and stir constantly to prevent any seizing. Using low heat or short bursts in the microwave works best.

Can I make these ahead of time?

Yes, I usually make them a day ahead—they slice even better after chilling overnight.

Conclusion

Reese’s Marshmallow Brownies are a decadent, crowd-pleasing treat that’s as easy to make as it is to love. With their rich brownie base, gooey marshmallow layer, and creamy peanut butter-chocolate topping, they deliver that over-the-top flavor I crave. Whether I’m baking for an event or just indulging at home, this recipe never disappoints.