These Peanut Butter Cup Rice Krispie Treats take the classic cereal bar up a notch. With gooey marshmallows, crunchy peanuts, chocolate cereal, and a double hit of peanut butter from chips and peanut butter cups, they’re sweet, salty, chewy, and crisp all at once.

They come together with just 30 minutes of prep—no oven required—and are a fun way to use up leftover Halloween candy!

Stack of three peanut butter cup rice krispie treats on a wooden board lined with parchment paper. The bars are thick and chewy, filled with chocolate puffed rice cereal, chopped peanuts, and bits of peanut butter cups. A few mini marshmallows and peanut butter chips are scattered at the bottom of the frame.

Before You Start Cooking

Prep and Measure Ahead. Have everything measured out and prepped, including your pan, before you start melting the butter. Once the marshmallows melt, the mixture comes together quickly.
Use Fresh Marshmallows. Older or partially dried marshmallows don’t melt as smoothly and can lead to firmer treats. For the softest, gooey texture, use a fresh bag.
Pan. You’ll need an 8×8-inch square baking pan. For easy treat removal and the cleanest slices, spray the pan lightly with cooking spray and line it with parchment, leaving a 2-inch overhang. If you’re not lining the pan, grease it well with cooking spray.

How to Make Peanut Butter Cup Rice Krispie Treats

Step 1: Melt the Butter and Marshmallows

In a large, heavy-bottomed pot (I like to use an enameled cast iron pot), melt unsalted butter over medium heat. As with all of my krispie treat recipes, you can use American-style butter or a higher-butterfat European-style butter, such as Plugrá or Kerrygold, for extra richness.

Once the butter is melted, reduce the heat to low. Stir in your miniature marshmallows with a rubber spatula until they’re about three-quarters melted.

Overhead view of a white Dutch oven filled with mini marshmallows beginning to melt in butter. The marshmallows are piled high and just starting to soften around the edges in preparation for rice krispie treats. — Mini marshmallows added to melted butter.

Turn off the heat and add a little salt (to balance the sweetness) and vanilla extract. Continue stirring until the mixture is smooth and glossy.

Tip: Don’t overheat the marshmallow mixture. If it starts bubbling, it’s too hot, and the treats may turn out firm and tough instead of soft and chewy.

A white pot filled with a smooth, melted marshmallow and butter mixture, partially foamy with visible marshmallow pieces. Bowls of chocolate puffed rice cereal, chopped peanuts, and peanut butter chips are arranged around the pot, ready to be stirred in. — Vanilla and salt added.

Step 3: Add the Cereal and Mix-Ins

Remove the pot from the heat and immediately fold in chocolate puffed rice cereal (Cocoa Krispies) and chopped, lightly salted dry-roasted peanuts.

Use a rubber spatula to gently fold the mixture until the cereal and peanuts are lightly coated in gooey marshmallow. It should look soft and glossy with strings of melted marshmallow as you stir—if it feels heavy or compact, you’ve mixed a little too much.

Chopped peanuts sprinkled on top of the partially mixed chocolate cereal and marshmallow mixture in a white Dutch oven. A spatula rests in the pot, and a bowl of peanut butter chips sits to the right. — Cereal and chopped peanuts added.

Let the mixture cool for just a minute or two, then fold in peanut butter chips until they’re evenly distributed. They should hold their shape without immediately melting.

Step 4: Press, Top, and Cool

Transfer the warm, sticky mixture to the prepared pan. Using a piece of parchment or the butter wrapper lightly misted with cooking spray, press the mixture gently into an even layer.

Don’t compact them too firmly—this keeps the bars chewy.

Sprinkle the top with roughly chopped Reese’s Peanut Butter Cups, pressing them lightly into the surface so they stick as the mixture sets. They’ll melt slightly from the warmth of the cereal mixture.

Let the treats cool at room temperature for 2 to 3 hours, until set and the peanut butter cups have firmed back up.

Close-up of uncut peanut butter cup rice krispie treats in a metal baking pan. The top is studded with chopped Reese’s peanut butter cups, visible peanut pieces, and pockets of melted marshmallow, all mixed with chocolate puffed rice cereal. The texture appears gooey and slightly crispy. — Pressed into the pan.

Once cooled, slice the treats into 9 or 16 squares, depending on how large you’d like them. (The batch shown here was cut into 9 squares, but since they’re rich, smaller bites are often just right.)

If you used a parchment sling, just lift the entire block of treats out of the pan and onto a cutting board for easy slicing. If you didn’t line the pan, you’ll likely need to cut the bars in the pan and remove them one at a time.

Overhead view of peanut butter cup rice krispie treats sliced into neat squares on a round wooden board lined with parchment paper. The treats are packed with chocolate puffed rice cereal, chopped peanuts, gooey marshmallow, and chunks of peanut butter cups. Scattered mini marshmallows, peanut butter chips, and cereal pieces frame the board. — Cooled and sliced.

Serving and Storage Tips

Serving: Peanut Butter Cup Rice Krispie Treats are decadent enough for dessert but casual enough for a snack table at a party. They’re great for Halloween gatherings or as a game day treat!
Storage: Keep the treats covered at room temperature for 3–4 days. Do not refrigerate—they’ll harden and lose their chewy texture.

Close-up of a hand lifting a gooey peanut butter cup rice krispie treat from a batch resting on parchment paper. The bar is studded with chopped peanut butter cups and peanuts, with visible strands of melted marshmallow stretching as the treat is pulled away.

More Rice Krispie Treat Recipes

More Chocolate and Peanut Butter Desserts

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Peanut Butter Cup Rice Krispie Treats

by Amanda Biddle

Sweet, salty, and chewy, these Peanut Butter Cup Rice Krispie Treats are loaded with marshmallows, chocolate cereal, and peanut butter cups for a decadent twist on the classic no-bake dessert.

Prep Time: 20

Cook Time: 10

Cooling Time: 1

Total Time: 1 30

Servings: 9 to 16 squares

Ingredients

▢ 8 tablespoons unsalted butter (see note)
▢ 10 ounces Jet-Puffed mini marshmallows
▢ ½ teaspoon vanilla extract
▢ ¼ teaspoon table salt
▢ 5 cups chocolate puffed rice cereal (Cocoa Krispies, 7½ ounces)
▢ ½ cup chopped dry roasted peanuts (I use lightly salted peanuts)
▢ ½ cup peanut butter chips
▢ 6 regular size Reeses Peanut Butter Cups , roughly chopped

Instructions

Prep the Pan. Lightly grease an 8×8-inch baking pan and line with parchment paper, leaving a 2-inch overhang on two sides. If you prefer not to line the pan, grease it with cooking spray, but you'll have to cut the treats in the pan rather than on a cutting board.
Melt the Marshmallows: In a large pot, melt butter over medium heat. Reduce heat to low and stir in the marshmallows until about three-quarters melted. Turn off heat, add salt and vanilla, and stir until the marshmallows are smooth.
Mix: Off the heat, fold in the cereal and peanuts until evenly coated. Let cool 1-2 minutes, then quickly fold in the peanut butter chips.
Assemble: Press the mixture gently into the prepared pan. (Use the butter wrapper or a piece of parchment sprayed with cooking spray to keep it from sticking to your hands.) Top with chopped Reese’s Peanut Butter Cups, and gently press them into the surface to adhere.
Set and Slice: Let stand at room temperature for 2-3 hours before slicing into 9 or 16 squares. Store covered at room temperature for up to 3 days.

Notes

Butter: Either American butter or a higher-butterfat European style (like Plugrá or Kerrygold) works well. The European varieties will make the treats extra indulgent.

Nutrition estimate calculated from cutting the treats into 9 squares.

Nutrition Estimate

Nutrition information is automatically calculated, so should only be used as an approximation.

About our recipes

Please note that our recipes have been developed using the US Customary measurement system and have not been tested for high altitude/elevation cooking and baking.

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