Buckeye Cookie Bars with Cake Mix are a fun twist on the classic chocolate‑peanut butter combo you love. This version starts with a box of chocolate cake mix for the base, adds a creamy peanut butter middle layer, and finishes with a glossy chocolate ganache. The result is rich, indulgent, and surprisingly straightforward to pull off in one 9×13 inch pan.
Why You’ll Love These Buckeye Cookie Bars
You’ll love these bars because they bring together three layers of texture and flavor: a cakey cookie base made with chocolate cake mix, a smooth peanut butter filling that echoes the beloved buckeye candy, and a silky chocolate ganache top. The combination hits chocolate lovers and peanut butter fans alike. Plus, using a cake mix in the cookie layer cuts baking time and effort, making this dessert approachable for weekday baking or special occasions.
Ingredients
For the Cookie Layer:
- 1 box chocolate cake mix
- ½ cup (1 stick) unsalted butter, melted
- 2 large eggs, room temperature
For the Peanut Butter Layer:
- 1 cup creamy peanut butter
- 1 cup powdered sugar
- ¼ cup unsalted butter, softened
- 1 tsp vanilla extract
For the Chocolate Ganache:
- 1½ cups semi sweet chocolate chips
- ¾ cup heavy cream
- a pinch of flaky sea salt (optional)
Step by Step: How to Make the Bars
- Preheat your oven to 350 °F (175 °C). Line a 9×13 inch baking dish with parchment paper, allowing the edges to hang over for easy lifting later.
- Make the cookie layer: In a large bowl, combine the chocolate cake mix, melted butter, and the eggs. Mix until well blended. Press the mixture evenly into the prepared pan.
- Bake the cookie layer for about 20 25 minutes, or until the edges are golden and a toothpick inserted into the center comes out clean. Remove from oven and let it cool completely in the pan on a wire rack.
- Prepare the peanut butter layer: In a medium bowl, beat together the peanut butter, powdered sugar, softened butter, and vanilla extract until smooth and creamy. Spread this mixture evenly over the cooled cookie layer.
- Make the chocolate ganache: To make the ganache, add chocolate chips to a heatproof bowl. Warm the heavy cream in a small saucepan over medium heat until it starts to gently simmer. Pour the heated cream over the chocolate chips and let it rest for 2 to 3 minutes. Then whisk until the chocolate is fully melted and the mixture is smooth and glossy.
- Assemble & chill: Pour the ganache over the peanut butter layer, spreading it evenly with a spatula. If using, sprinkle a pinch of flaky sea salt over the ganache before it sets. Chill the bars in the fridge for at least 2 hours, or until the ganache has fully firmed up.
- Serve: Once set, use the parchment overhang to lift the whole slab out of the pan. Cut into squares or rectangles and serve. Enjoy your scrumptious bars!
Helpful Tips
- Make sure the cookie layer is completely cooled before adding the peanut butter layer—this helps prevent the peanut butter mixture from melting or becoming runny.
- When melting the ganache, resist the urge to overheat the cream; once it begins to shimmer or just starts to simmer is ideal. Pour it over the chocolate chips right away for a smooth result.
- If you’re worried about the ganache cracking when you slice, wait until it is firm but not rock hard before cutting. Some sources suggest scoring the chocolate gently when just set, and then refrigerating further.
- Use a sharp, clean knife for cutting, wiping the blade between cuts for clean lines.
- For easiest removal, be sure the parchment paper overhang is generous and you pull the slab out fully before slicing.
Substitutions And Variations
- Peanut butter alternative: For those avoiding peanuts, you could substitute almond butter or cashew butter, though texture will vary slightly.
- Cake mix flavour change: Instead of chocolate cake mix, try a devil’s food cake mix or a chocolate fudge cake mix for deeper chocolate flavor.
- Topping variations: Instead of plain ganache, swirl in a bit of caramel or sprinkle chopped nuts or pretzels on top before setting for added crunch.
- Ganache twist: Use dark chocolate chips (70 % cocoa) if you prefer a less sweet topping, or milk chocolate for more sweetness.
- Gluten free option: Use a gluten free chocolate cake mix for the cookie layer and verify all other ingredients are gluten free.
Storage Instructions
Keep the bars in an airtight container stored in the refrigerator. They stay fresh longer when properly covered and refrigerated. If you prefer, you can freeze them: wrap individual bars or the whole slab (cut or uncut) in plastic wrap then foil, and freeze for up to 2 months. To serve, thaw in the fridge overnight or at room temperature for about 30 minutes. If frozen, you may want to slice after partial thawing to prevent ganache cracking.
Nutritional Information
- Calories: ~306.6 kcal
- Fat: ~21.3 g
- Saturated Fat: ~9.6 g
- Carbohydrates: ~26.5 g
- Fiber: ~1.8 g
- Net Carbs: ~24.7 g
- Sugar: ~17.2 g
- Protein: ~4.95 g
- Sodium: ~206 mg
- Cholesterol: ~39.8 mg
Serving Suggestions
- Serve the bars slightly chilled for a firm texture, or allow them to sit at room temperature for ~10 minutes before serving for a softer bite.
- Pair with a cold glass of milk, coffee, or a light dessert wine.
- For a festive presentation, cut into small bite sized squares and arrange on a platter — perfect for parties or gatherings.
- You can top each bar with a mini peanut butter cup, chopped roasted peanuts, or a drizzle of white chocolate for extra flair.
Frequently Asked Questions About Buckeye Cookie Bars
Can I make these bars ahead of time?
Yes! You can bake the cookie layer and prepare the peanut butter layer ahead, then assemble the ganache and refrigerate until ready to serve. They will hold well if covered and kept chilled.
My chocolate ganache cracked when I cut it — what happened?
This can happen if the ganache layer becomes too firm and brittle before slicing. To avoid this, you can allow the ganache layer to just set at room temperature, score your cut lines lightly with a knife, then refrigerate until serving. Some sources note this method helps prevent cracking.
Can I skip the cake mix cookie layer and just do peanut butter + ganache?
Yes — many “buckeye bars” recipes are no bake and consist of a peanut butter layer topped with chocolate. However, using the cake mix layer adds more structure, gives a slightly cakier texture, and adds volume.
My peanut butter mixture seemed too soft / oily. How can I fix that?
If you use a natural peanut butter with separated oil, it may make the mixture too loose. Use a stable creamy peanut butter (with no oil separation) and ensure the butter is properly softened (not melted) before mixing. Some bloggers suggest avoiding “natural” peanut butter for this reason.
Can I make this vegan or dairy-free?
Yes, you can try:
- Use vegan butter or margarine in place of unsalted butter.
- Substitute heavy cream with a non-dairy alternative like coconut cream for the ganache (be aware that the texture may differ).
- Use dairy-free chocolate chips. The taste will still be great, though the consistency may be a bit different.
Final Thoughts
Thank you so much for trying this Buckeye Cookie Bars with Cake Mix recipe — it’s one of my favorite indulgent desserts to make because it’s easy, flavorful, and always impresses. I hope you enjoy the rich combination of the chocolate cake mix base, creamy peanut butter layer, and glossy ganache just as much as I do. Thanks for being part of this food-loving community, and here’s to your next baking adventure — may it be full of ease, flavor, and joy. Happy baking!
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Buckeye Cookie Bars
- Total Time: 2 hours 45 minutes (includes chilling)
- Yield: 12 to 15 bars 1x
Description
Buckeye Cookie Bars with Cake Mix are a quick and crowd-pleasing dessert layered with chocolate cake cookie, creamy peanut butter, and ganache
Ingredients
For the Cookie Layer:
1 box chocolate cake mix
½ cup (1 stick) unsalted butter, melted
2 large eggs, room temperature
For the Peanut Butter Layer:
1 cup creamy peanut butter
1 cup powdered sugar
¼ cup unsalted butter, softened
1 tsp vanilla extract
For the Chocolate Ganache:
1½ cups semi sweet chocolate chips
¾ cup heavy cream
a pinch of flaky sea salt (optional)
Instructions
- Preheat your oven to 350 °F (175 °C). Line a 9×13 inch baking dish with parchment paper, allowing the edges to hang over for easy lifting later.
- Make the cookie layer: In a large bowl, combine the chocolate cake mix, melted butter, and the eggs. Mix until well blended. Press the mixture evenly into the prepared pan.
- Bake the cookie layer for about 20 25 minutes, or until the edges are golden and a toothpick inserted into the center comes out clean. Remove from oven and let it cool completely in the pan on a wire rack.
- Prepare the peanut butter layer: In a medium bowl, beat together the peanut butter, powdered sugar, softened butter, and vanilla extract until smooth and creamy. Spread this mixture evenly over the cooled cookie layer.
- Make the chocolate ganache: To make the ganache, add chocolate chips to a heatproof bowl. Warm the heavy cream in a small saucepan over medium heat until it starts to gently simmer. Pour the heated cream over the chocolate chips and let it rest for 2 to 3 minutes. Then whisk until the chocolate is fully melted and the mixture is smooth and glossy.
- Assemble & chill: Pour the ganache over the peanut butter layer, spreading it evenly with a spatula. If using, sprinkle a pinch of flaky sea salt over the ganache before it sets. Chill the bars in the fridge for at least 2 hours, or until the ganache has fully firmed up.
- Serve: Once set, use the parchment overhang to lift the whole slab out of the pan. Cut into squares or rectangles and serve. Enjoy your scrumptious bars!
Notes
Use flaky salt for contrast, chill before slicing, and use non-natural peanut butter for best results.
- Prep Time: 20 minutes
- Cook Time: 25 minutes
- Category: Dessert
Nutrition
- Serving Size: 1 bar
- Calories: 306
- Sugar: 17.2 g
- Carbohydrates: 26.5 g
- Protein: 4.95 g