Buckeye Brownies

Name: Buckeye Brownies
Prep time: 25 min
Cook time: 30 min
Ingredients: 1 box supreme brownie mix; eggs (according to box instructions); water (according to the box instructions); oil (according to the box instructions); ½ Cup butter (softened); ½ Cup creamy peanut butter; 2 Cups powdered sugar; 3-4 Tablespoons milk; 1 Cup semi sweet chocolate chips; ¼ Cup butter

This buckeye brownies recipe is one I reach for when I want something rich, fudgy, chewy, but easy to pull together. The soft chocolately brownie base, creamy peanut butter layer, and glossy chocolate topping make every bite feel complete.

Table of Contents

Sweet Layers That Stay Together

Some of the very best desserts come from the most unexpected places, and this buckeye brownies recipe is proof. I found it tucked into a community cookbook from our local elementary school, the page slightly smudged. That’s always a sign a recipe has been loved and baked often.

old recipe for buckeye brownies found in cookbook

The peanut butter filling is creamy and sweet without feeling heavy, and the smooth chocolate topping sets into a shiny, bakery-worthy finish. I like to chill the pan before cutting, just like I do with my homemade fudgy brownies, which keeps the squares neat and tidy… though a few always disappear before sharing.

Just like my peanut butter chocolate chip brownies, these brownies can be made a day ahead and somehow get even better as they rest. The flavors settle, the texture softens, and one bite takes me straight back to school bake sales and potluck tables.

ingredients to make buckeye brownies on kitchen counter

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Key Ingredients and Substitutions

Brownie mix: The base of these buckeye brownies starts with a boxed brownie mix. I like using a “supreme” mix for that extra fudgy texture, but any brand you enjoy will work just fine.
Eggs, water, and oil: These bring the brownie mix together and give it the right texture. Just follow the amounts listed on your box — it keeps things simple and consistent.
Butter: Helps make the peanut butter layer smooth and spreadable. If you only have unsalted butter, just add a small pinch of salt to balance the sweetness. It’s also used in the topping.
Creamy peanut butter: The star of the middle layer. It adds that classic buckeye flavor and creamy texture. You can use natural peanut butter if you stir it well, but the regular kind blends easiest.
Powdered sugar: Sweetens and thickens the peanut butter layer so it holds its shape. If your sugar is clumpy, give it a quick sift before mixing.
Milk: Loosens up the peanut butter mixture just enough to make it silky and easy to spread. Start with a little and add more if you need a softer texture.
Semi-sweet chocolate chips: Melted with butter, these create the glossy top layer. You can use milk chocolate chips if you prefer a sweeter finish.

How to Make Buckeye Brownies

Preparation

Preheat your oven to 350°F. Line the bottom of a 9×13-inch baking pan with parchment paper and lightly grease just the bottom. Set out all ingredients so they’re ready to use, and make sure the butter for the peanut butter layer is softened.

Step 1 – Mix the Brownie Batter

In a medium bowl, combine the brownie mix, eggs, water, and oil according to the directions on your box. Stir until the batter is smooth and no dry streaks remain. The mixture should look thick and glossy.

Step 2 – Bake the Brownies

Pour the brownie batter into the prepared pan and spread it evenly with a spatula. Bake for 28–30 minutes, or until a toothpick inserted in the center comes out mostly clean with just a few moist crumbs. Let the brownies cool completely in the pan before moving to the next step.

whipped peanut butter and powdered sugar in bowl

Step 3 – Make the Peanut Butter Layer

In a clean mixing bowl, beat together the softened butter, creamy peanut butter, powdered sugar, and milk using a hand mixer on medium speed. Mix until smooth and creamy, about 2 minutes. Spread the peanut butter mixture evenly over the cooled brownies, pressing gently to create an even layer.

Step 4 – Melt the Chocolate Topping

In a small microwave-safe bowl, combine the chocolate chips and butter. Microwave for 30 seconds, stir, then microwave for another 30 seconds. Stir again until the mixture is silky smooth and fully melted.

Step 5 – Add the Chocolate Layer

Pour the melted chocolate over the peanut butter layer and spread it evenly with a spatula. Let the pan sit at room temperature until the chocolate sets, or place it in the refrigerator for faster firming. Once set, slice into squares and serve.

Lynette’s Tip

For the cleanest slices, chill the finished brownies in the refrigerator for about 30 minutes before cutting. Use a sharp knife and wipe it clean between each cut for neat, bakery-style squares that make you proud to share (or keep to yourself!).

Recipe FAQs

Can I bake these in a smaller pan?

Yes, an 8×8-inch pan works well if you want thicker layers. The baking time may increase slightly, so check for doneness with a toothpick.

How do I get clean, even slices?

Chill the brownies in the refrigerator for about 30 minutes before cutting. Use a sharp knife and wipe it clean between each slice for neat, bakery-style squares.

Why did my chocolate layer crack when cutting?

That can happen if the chocolate is too cold or set too firmly. Let the brownies sit at room temperature for a few minutes before slicing to soften the top slightly.

What kind of chocolate chips should I use?

Semi-sweet chocolate chips give a nice balance of sweetness, but you can use milk or dark chocolate if you prefer. Choose a good-quality brand so the topping melts smoothly.

Buckeye Brownies

Sweet Layers That Stay Together

Key Ingredients and Substitutions

How to Make Buckeye Brownies

Lynette’s Tip