Reeses Marshmallow Brownies
There’s something incredibly indulgent about the combination of brownies, marshmallows, and Reese’s. When you take a bite of these Reeses Marshmallow Brownies, you’re met with layers of rich chocolate, creamy peanut butter, and gooey marshmallow that create an irresistible dessert experience. Whether you’re a chocolate lover, a peanut butter enthusiast, or just someone who enjoys sweet treats, this recipe is sure to become a favorite in your kitchen. They’re perfect for birthdays, potlucks, or a simple weekend treat at home. Let’s dive into this sweet adventure!
Why It’s My Go-To

These Reeses Marshmallow Brownies have earned a special place in my recipe book for several reasons. First, they are incredibly easy to make, even for novice bakers. The use of a brownie mix cuts down on prep time, allowing you to focus on the fun parts—like adding marshmallow fluff and Reese’s! Second, they are crowd-pleasers. Whenever I bring these to gatherings, they disappear within minutes, leaving everyone reaching for seconds. Lastly, the flavor combination of chocolate, peanut butter, and marshmallow is simply heavenly. It’s hard to resist a dessert that delivers such a delightful taste experience.
What We’re Using
To make these decadent Reeses Marshmallow Brownies, gather the following ingredients:
- 18 ounces brownie mix
- 1/4 cup water (or as directed on the brownie mix package)
- 1/2 cup vegetable oil (or as directed on the brownie mix package)
- 3 eggs (or as directed on the brownie mix package)
- 7 ounces marshmallow creme or fluff
- 25 Reese’s miniatures, halved
- 12 ounces semi-sweet chocolate chips
- 1 cup creamy peanut butter (do not use natural)
- 3 cups crispy rice cereal
Prep & Cook Tools
Before we start baking, make sure you have the following tools on hand:
- Large mixing bowl: For combining your brownie mix ingredients.
- 9×13 inch baking pan: To bake those delicious brownies in.
- Spatula: For spreading the brownie batter evenly.
- Microwave-safe bowl: To melt the chocolate and peanut butter mixture.
- Measuring cups and spoons: For accurate ingredient measurements.
- Cooling rack: To allow the brownies to cool properly after baking.
Reeses Marshmallow Brownies: Step-by-Step Guide

Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C). This ensures that the brownies bake evenly and come out perfectly fudgy.
Step 2: Prepare the Brownie Batter
In a large mixing bowl, combine the brownie mix, water, vegetable oil, and eggs. Stir until just combined, being careful not to overmix. The batter should be thick and glossy.
Step 3: Bake the Brownies
Pour the brownie batter into a greased 9×13 inch baking pan, spreading it evenly. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Step 4: Add the Marshmallow Fluff
Remove the brownies from the oven and let them cool for about 10 minutes. Dollop the marshmallow fluff evenly over the top of the brownies, spreading it gently with a spatula.
Step 5: Prepare the Peanut Butter Mixture
In a microwave-safe bowl, combine the chocolate chips and creamy peanut butter. Microwave in 30-second intervals, stirring in between, until melted and smooth.
Step 6: Add the Crispy Rice Cereal
Once the chocolate-peanut butter mixture is melted, stir in the crispy rice cereal until fully coated. This mixture will add a delightful crunch to the brownies.
Step 7: Top the Brownies
Spread the chocolate-peanut butter and crispy rice mixture over the marshmallow layer. Then, press the halved Reese’s miniatures gently into the top.
Step 8: Final Bake
Return the brownies to the oven and bake for an additional 10-15 minutes, or until the topping is set and slightly golden.
Step 9: Cool and Cut
Allow the brownies to cool completely in the pan on a wire rack before cutting them into squares. This will help the layers set and make for cleaner cuts.
Allergy-Friendly Swaps

If you have dietary restrictions or allergies, here are some easy swaps to make these Reeses Marshmallow Brownies more accommodating:
- Gluten-Free: Use a gluten-free brownie mix.
- Dairy-Free: Substitute semi-sweet chocolate chips with dairy-free chocolate chips and use a non-dairy spread in place of peanut butter.
- Nut-Free: Replace peanut butter with sun butter or a similar nut-free spread.
- Vegan: Use flax eggs in place of regular eggs and a vegan brownie mix.
Troubleshooting Tips
If you encounter any issues while making your Reeses Marshmallow Brownies, here are some tips to help:
- If your brownies are too dry, ensure you’re measuring the ingredients accurately, and avoid overbaking.
- If the marshmallow fluff is too sticky, lightly grease your spatula before spreading it.
- If the topping seems too gooey, let the brownies cool longer before cutting.
- To avoid a crumbly mess, use a sharp knife, and clean it between cuts.
Storing, Freezing & Reheating
To keep your Reeses Marshmallow Brownies fresh and delicious, follow these storage tips:
- Storing: Keep the brownies in an airtight container at room temperature for up to 4 days.
- Freezing: Wrap individual squares in plastic wrap and place them in a freezer-safe bag. They can be frozen for up to 3 months.
- Reheating: To enjoy them warm, microwave for 15-20 seconds until just heated through.
Popular Questions
Can I use a different type of brownie mix?
Absolutely! You can use any flavor of brownie mix you prefer, such as fudge, walnut, or even blondie mix for a twist.
What if I can’t find marshmallow fluff?
If marshmallow fluff is unavailable, you can make a simple marshmallow layer by melting mini marshmallows with a bit of butter and then spreading them over the brownies.
Can I add nuts to the recipe?
Yes! Feel free to toss in chopped nuts like peanuts or walnuts into the brownie batter or sprinkle them on top for added crunch.
How do I know when the brownies are done baking?
The brownies are done when a toothpick inserted into the center comes out with a few moist crumbs. It’s okay if it’s not completely clean; that’s what makes them fudgy!
Ready, Set, Cook
Now that you have all the steps laid out, it’s time to gather your ingredients and get baking! These Reeses Marshmallow Brownies are a delightful treat that will bring joy to any gathering or simply satisfy your sweet tooth at home. With their rich chocolate base, fluffy marshmallow topping, and crunchy peanut butter layer, they are a treat worth sharing—or keeping all to yourself! Enjoy the process, and most importantly, enjoy every delicious bite of these brownies!

Reeses Marshmallow Brownies
Ingredients
Equipment
Method
- Step 1: Preheat your oven to 350°F (175°C) to ensure even baking.
- Step 2: In a large mixing bowl, combine the brownie mix, water, vegetable oil, and eggs. Stir until just combined.
- Step 3: Pour the brownie batter into a greased 9x13 inch baking pan and bake for 25-30 minutes.
- Step 4: Remove from the oven and let cool for 10 minutes, then spread the marshmallow fluff on top.
- Step 5: In a microwave-safe bowl, combine chocolate chips and peanut butter, melting in intervals until smooth.
- Step 6: Stir in crispy rice cereal until fully coated.
- Step 7: Spread the chocolate-peanut butter mixture over the marshmallow layer, pressing halved Reese's on top.
- Step 8: Bake again for 10-15 minutes until the topping is set and slightly golden.
- Step 9: Cool completely on a wire rack before cutting into squares.
Notes
- Store brownies in an airtight container at room temperature for up to 4 days.
- Wrap individual squares in plastic wrap and freeze for up to 3 months.
- Microwave for 15-20 seconds to enjoy warm.
