Buckeye brownies are a three layer bar: a fudgy cocoa brownie base, a no bake peanut butter layer, and a thin sheet of chocolate ganache on top. It is the flavor of buckeye candy without rolling and dipping a single ball. This recipe bakes in a 9×9 inch pan at 350°F for 28 to 32 minutes, chills for about 2½ hours in total, and cuts into 16 squares.
The one rule is patience between layers. Cool the base completely, chill the peanut butter layer for 30 minutes, and only then pour the ganache. If you love the candy itself, my buckeyes recipe uses almost the same peanut butter mixture.
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Try the Recipe Converter →The Three Layers, Measured Out
- Brownie base: 1 cup melted butter, 1½ cups granulated sugar, ¾ cup brown sugar, 4 eggs, 2 teaspoons vanilla, 1 cup flour, ¾ cup cocoa powder, ½ teaspoon salt
- Peanut butter layer: 1 cup creamy peanut butter, ½ cup softened butter, 2 cups powdered sugar, 1 teaspoon vanilla
- Ganache: 1 cup semi-sweet chocolate chips and ½ cup heavy cream, a 2 to 1 ratio by volume
- Pan and yield: 9×9 inch pan lined with parchment, 16 squares about 2¼ inches each
- Time: 25 minutes prep, 28 to 32 minutes baking, 30 minutes chilling before the ganache and at least 2 hours after
There are no chips or nuts in the base, so the cocoa does all the chocolate work. Use a good unsweetened cocoa, the same kind you would use for cocoa powder brownies.
Mixing the Fudgy Cocoa Base
Whisk the melted butter with both sugars until smooth, then whisk in the eggs and vanilla. Stir in the flour, cocoa and salt by hand only until no dry streaks remain. Beating it longer adds air and makes the base cakey, and a cakey base crumbles under the filling.
This is a deep batter for a 9×9 pan. Trust the toothpick over the clock: near the center it should come out with a few moist crumbs, and the top should look set with no jiggle. If you still see wet batter at 32 minutes, give it 3 to 5 more minutes. Then let the pan cool completely, about an hour. Warm brownie melts the butter in the filling and the layer slides.
Peanut Butter Middle: Creamy or Natural?
Use regular creamy peanut butter, the stirred kind from a jar. It stays emulsified, so the filling beats up smooth and sets firm in the fridge. Natural peanut butter separates. The oil seeps out, the layer turns greasy and soft, and it never quite holds a clean edge between brownie and chocolate.
Beat the peanut butter and softened butter first until fluffy, with no butter streaks. Then add the powdered sugar and vanilla. The filling is right when it looks like thick frosting and holds a spoon mark. Spread it edge to edge with an offset spatula and chill the pan for 30 minutes. It is ready when it feels firm and does not stick to your fingertip.
Pouring the Ganache Without Melting the Filling
Heat the cream until it steams with small bubbles at the edge, not a full boil. Pour it over the chips, wait 2 minutes, then stir until glossy. Now let it stand about 5 minutes. Hot ganache softens the butter in the peanut butter layer and the two blur together. Warm ganache sits on top.
Pour it over the cold filling and nudge it to the corners. Add chopped peanuts or chocolate shavings while it is still soft, so they stick. A few flakes of sea salt work too. For a thicker topping on other bakes, my chocolate ganache recipe explains how the ratio changes the set.
Cutting 16 Tidy Buckeye Squares
Chill the pan for at least 2 hours, until the ganache is matte and firm. Lift the slab out with the parchment overhang. Cut it into 4 strips, then each strip into 4. Dip a sharp knife in hot water, wipe it dry, and press straight down for every cut. Sawing drags chocolate into the peanut butter.
When the Layers Misbehave
- Filling too soft or greasy: beat in powdered sugar 2 tablespoons at a time until it holds a spoon mark. Warm peanut butter or a hot kitchen does this too, so chill the bowl 10 minutes first.
- Filling too stiff to spread: beat in a teaspoon of cream, or warm the bowl for a few seconds.
- Filling slid off the base: the brownie was still warm. Chill the pan, then smooth the layer back into place.
- Ganache looks grainy or oily: the cream boiled. Whisk in a tablespoon of warm cream to bring it back.
- Topping cracks when you cut: the squares are fridge cold. Let them sit 10 minutes, then cut with a warm knife.
Storing and Freezing Buckeye Brownies
Keep them covered in the fridge for up to 5 days. Cold squares hold their layers, which makes them good for packing in a tin or taking to a party. Serve them chilled, or leave them out 10 minutes if you like the ganache softer.
To freeze, wrap the squares well and freeze for up to 2 months. Thaw overnight in the fridge. The whole pan can be made a day ahead and cut the morning you serve it.
Next time you want this flavor in another shape, try Reese’s peanut butter cake, peanut butter cup cookies or a pan of peanut butter fudge. For a simpler bar, peanut butter brownies skip the ganache.
Buckeye Brownie Questions
Do buckeye brownies need to be refrigerated?
Yes. The peanut butter layer and ganache soften at room temperature, so keep them covered in the fridge for up to 5 days.
Can I use a boxed brownie mix for the base?
Yes. Bake a fudgy family size mix in the 9×9 pan as the box directs, cool it completely, then add the peanut butter layer and ganache as written.
Can I make buckeye brownies in a 9×13 pan?
You can, but every layer will be thinner. Start checking the base at about 20 minutes, or make 1½ batches for the same thickness.
How many squares does one pan make?
Sixteen squares of about 2¼ inches. The bars are rich, so you can cut 25 smaller pieces for a dessert tray.
Buckeye Brownies
These buckeye brownies are layered peanut butter brownies made with a fudgy cocoa brownie base, a creamy peanut butter and powdered sugar layer, and a semi-sweet chocolate ganache. They bake in a 9x9 inch pan at 350°F for 28 to 32 minutes, chill for about 2½ hours, and cut into 16 squares with thick, clean layers. The base cools completely and the peanut butter layer chills 30 minutes before the warm ganache goes on, so the layers stay separate. Serve them on holiday cookie trays, at bake sales, for game day, or as a buckeye candy bar for anyone who loves chocolate and peanut butter. Use regular creamy peanut butter, not natural. Keep them in the fridge 5 days or freeze 2 months.
Ingredients
- FOR THE BROWNIE LAYER
- 1 cup unsalted butter, melted
- 1½ cups granulated sugar
- ¾ cup brown sugar
- 4 large eggs
- 2 teaspoons vanilla extract
- 1 cup all-purpose flour
- ¾ cup unsweetened cocoa powder
- ½ teaspoon salt
- FOR THE PEANUT BUTTER LAYER
- 1 cup creamy peanut butter
- ½ cup unsalted butter, softened
- 2 cups powdered sugar
- 1 teaspoon vanilla extract
- FOR THE CHOCOLATE TOPPING
- 1 cup semi-sweet chocolate chips
- ½ cup heavy cream
- FOR THE OPTIONAL GARNISH
- Chopped peanuts
- Chocolate shavings
Instructions
PREPARE THE BROWNIE LAYER: Preheat the oven to 350°F (175°C). Line a 9x9-inch baking pan with parchment paper, leaving an overhang for easy removal. In a large mixing bowl, whisk together the melted butter, granulated sugar, and brown sugar until smooth. Add the eggs and vanilla extract and whisk until fully combined. Stir in the flour, cocoa powder, and salt until a thick batter forms with no dry streaks remaining.
BAKE THE BROWNIES: Spread the batter evenly into the prepared pan and smooth the surface. Bake for 28–32 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs attached. Remove from the oven and allow the brownies to cool completely in the pan.
MAKE THE PEANUT BUTTER FILLING: In a large mixing bowl, beat together the creamy peanut butter and softened butter until smooth and fluffy. Add the powdered sugar and vanilla extract and continue mixing until the filling is thick, creamy, and fully combined.
ADD THE PEANUT BUTTER LAYER: Spread the peanut butter mixture evenly over the cooled brownie layer. Use an offset spatula or the back of a spoon to create a smooth, level surface. Refrigerate for 30 minutes to help the layer firm up before adding the topping.
PREPARE THE CHOCOLATE GANACHE: Place the semi-sweet chocolate chips in a heatproof bowl. Heat the heavy cream until hot but not boiling, then pour it over the chocolate chips. Let the mixture stand for 2 minutes before stirring until smooth, glossy, and completely melted.
ADD THE CHOCOLATE TOPPING: Pour the ganache over the chilled peanut butter layer. Spread it evenly to the edges, creating a smooth and shiny surface.
GARNISH THE BROWNIES: Sprinkle chopped peanuts or chocolate shavings over the ganache while it is still soft so the garnish adheres to the surface.
CHILL AND SERVE: Refrigerate the brownies for at least 2 hours, or until the layers are fully set. Lift the brownies from the pan using the parchment overhang, cut into 16 squares with a sharp knife, and serve chilled or at cool room temperature.
Notes
Let the brownie base cool completely, about 1 hour, before adding the filling, or the peanut butter layer will slide.
Use regular creamy peanut butter. Natural peanut butter separates and makes the filling greasy and soft.
If the filling is too soft, beat in powdered sugar 2 tablespoons at a time; if too stiff, beat in a teaspoon of cream.
Let the ganache stand about 5 minutes after stirring so it is warm, not hot, before pouring over the chilled filling.
For clean slices, chill at least 2 hours, dip a sharp knife in hot water, wipe it dry, and cut straight down.
Store covered in the refrigerator for up to 5 days. Freeze wrapped squares for up to 2 months and thaw overnight in the refrigerator.
A sprinkle of flaky sea salt on the soft ganache adds contrast to the sweet layers.
Nutrition Information
Yield
16Serving Size
1Amount Per Serving Calories 746Total Fat 37gSaturated Fat 18gUnsaturated Fat 18gCholesterol 106mgSodium 170mgCarbohydrates 99gFiber 5gSugar 75gProtein 10g
