Crunchy Brownies are rich, fudgy chocolate brownies topped with marshmallow fluff and a crisp, crackly, chocolate peanut butter Rice Krispie layer that adds a satisfying crunch to every gooey bite!

Looking for more ways to level up a classic brownie? Check out my Reese’s Brownie Bites, Chocolate Covered Strawberry Brownies, Almond Joy Brownie Bites, Snickers Brownie Bites, Brownie Batter Bark, and S’mores Brownie Bites!

Why you’ll love this recipe:

If you’re searching for the best Crunchy Brownies, you just found them! These ultra-decadent brownies are topped with fluffy marshmallow and a thick layer of chocolate peanut butter Rice Krispies for the ultimate brownies and rice krispies treat mashup.

They’re rich, gooey, crunchy, and ridiculously easy to make using a store-bought brownie mix. Whether you need a crowd-pleasing dessert for a party, bake sale, holiday tray, or just a serious chocolate craving, these marshmallow Rice Krispie brownies will steal the show.

Ingredients you’ll need:

Store-brought brownie mix- prepared and baked according to box instructions
Marshmallow fluff
Semi-sweet chocolate chips
Creamy peanut butter
Rice Krispies cereal

The magic of these chocolate crunch brownies is how simple they are to make while still being completely over-the-top in the best way. You start with a store-bought brownie mix, which makes this recipe incredibly easy and reliable. No complicated steps. No fancy techniques. Just a fudgy chocolate base that sets the stage for something seriously irresistible.

Once the brownies come out of the oven, you spread marshmallow fluff right over the warm surface. It softens slightly and melts into the top layer, creating that creamy middle that makes these marshmallow fluff brownies so addictive. Then comes the real star: a chocolate and peanut butter Rice Krispie mixture that gets spread over the top and pressed gently into place.

What you end up with is the ultimate brownies and Rice Krispies treat mashup!

How to make the best Crunchy Brownies:

Prepare your brownies according to the directions on the box, then bake in a greased 9×13 baking pan. Once baked, let the brownies cool completely.
Spread your marshmallow fluff into an even layer on top of the brownies, then set aside.
In a microwave safe bowl, combine semi-sweet chocolate chips and peanut butter. Microwave in 30 second intervals, stirring in between, until melted and smooth.
Fold in the Rice Krispies cereal, then spread the Rice Krispies mixture on top of the marshmallow fluff.
Transfer the brownies to the fridge for 1 hour, then slice into squares before enjoying.

The bottom layer is dense and deeply chocolatey. The middle is soft and sweet with that nostalgic marshmallow flavor. The top layer is crunchy, chewy, and packed with chocolate peanut butter goodness. Every bite has contrast. Fudgy meets crispy. Rich meets sweet. It’s the kind of texture combination that keeps you reaching for “just one more” square.

These peanut butter Rice Krispie brownies are also a total crowd-pleaser. Bring them to a party and they disappear fast. Put them on a holiday dessert table and people will ask who made them. They travel well, slice beautifully once set, and look impressive with those clean, distinct layers.

If you love chocolate and peanut butter together, this recipe is especially hard to resist. The peanut butter cuts through the sweetness of the marshmallow and balances the richness of the brownie. The crispy cereal adds that signature crunch that makes these brownies topped with Rice Krispies stand out from every other layered brownie bar out there!

Crunchy Brownies aren’t just another brownie recipe. They’re a full dessert experience. Gooey, crunchy, sweet, and chocolatey all at once!

My top tips:

BROWNIE MIX: You already know I had to throw a shortcut in here somewhere so we’re using a boxed brownie mix to make this recipe even easier! Just be sure you use an 18 oz box and bake it in a 9×13 pan. If you’d like to make your brownies from scratch, use a recipe that traditionally fits a 9×9 pan so that the brownie layer is not too thick.
COOLING: It’s important to let the brownies cool completely before topping them with your marshmallow fluff and Rice Krispie mixture. If you top warm brownies, the brownies will likely sink and become soggy.
CHOCOLATE: I recommend heating the chocolate and peanut butter in 30 second intervals because the chocolate can burn and seize easily. It’s hard to reverse clumpy chocolate, so I recommend watching it closely! You can also use a double boiler here instead of the microwave.
CHILLING: If you’re impatient like me, you’re going to want to transfer your Crunchy Brownies into the fridge to make the toppings set up faster. You can let these set at room temperature, but it will take a few hours for the Rice Krispie layer to fully set up.
SLICING: The longer you leave these Crunchy Brownies in the fridge, the better they will slice. If you can, I even recommend making them a day ahead of time and letting them chill overnight so that the layers have time to solidify before slicing.
STORING: To store Crunchy Brownies, keep them in an airtight container at room temperature for up to 5 days, or in the refrigerator for up to a week to keep the topping firm.

Looking for more peanut butter and chocolate treats? Check these out!

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