This fun chocolate peanut butter cake with a fluffy pb filling is a celebration style layer cake that’s guaranteed to make a lot of people very happy!

a layer cake from a single 9×13 pan
Chocolate peanut butter cake is devil’s food cake filled with a sweet peanut butter cream and coated in chocolate icing. If you’ve ever had a Funny Bonesยฎ you’ll know how intensely delicious this is. It starts by baking (the best!) chocolate cake in a 9×13 pan. That cake is sliced in half and one half is layered on top of the other. It’s glazed and then sliced in half a final time to make the cutest little chocolate peanut butter cake slices you’ve ever seen. I can’t decide which is better…the soft chocolate cake layers or the billows of sweet peanut butter cream…I guess I’ll have to call it a delicious tie ๐ค๐ฅ
chocolate peanut butter cake baking steps
This unique square layer cake is made in a single 9×13 pan, here’s how it works:
- Bake the cake in a 9×13 pan (line with parchment for easy removal.)
- Cool and then slice in half.
- Fill with peanut butter cream filling.
- Glaze with chocolate glaze.
- Slice and enjoy!
The components of this chocolate peanut butter cake are tried and true!
- The cake is adopted from Ina Gartenโs Chocolate Cake Recipe
- The pb cream filling is adapted from my Peanut Butter Frosted Brownies
- The glaze is a chocolate ganache adapted from classic chocolate truffles
make it ahead
This is a great party cake to make a day ahead, it will be fine hanging out in the fridge overnight. You can serve it chilled or bring it up to temperature on the counter if you prefer.
chocolate peanut butter cake shortcut
Make this with a chocolate cake mix! With that luscious peanut butter filling and chocolate ganache glaze no one will know (or care!) trust me.
love this square layer cake?
I have lots more celebration cake recipes to check out for summer birthdays, cookouts, potlucks and picnics:
Chocolate Peanut Butter Cake
Equipment
- 9×13 cake pan
- parchment paper
- electric beaters for the peanut butter filling
Ingredients
Dry Ingredients
- 1 3/4 cup all purpose flour
- 2 cups sugar
- 3/4 cup unsweetened cocoa powder, I used Droste
- 2 tsp baking soda
- 1 tsp baking powder
- 1 tsp salt
Wet Ingredients
- 1 cup half and half
- 1/2 cup vegetable oil
- 2 large eggs
- 1 Tbsp vanilla extract
- 1 cup brewed coffee, warm or room temperature
peanut butter filling
- 2/3 cup creamy peanut butter *, I use Jiffยฎ
- 4 Tbsp salted butter, softened
- 1 Tbsp vanilla extract
- 2 cups powdered sugar, no need to sift
- 7 Tbsp half and half, or more if needed
- extra salt to taste
chocolate glaze
- 1 cup dark or semi sweet chocolate , use chopped bar chocolate, chocolate chips, or melting wafers
- 1/3 cup heavy cream
- 2 Tbsp butter
Instructions
For the cake
- Preheat oven to 350F. Spray and line your 9×13 pan with parchment paper so you can easily lift the cake out after baking and cooling.
- Whisk all the dry ingredients together well in a large bowl. Make sure to whisk out any lumps in the cocoa powder.
- In a separate bowl, whisk together all the wet ingredients.
- Add the wet ingredients to the dry ingredients, whisking as you go. Mix everything until there are no pockets of dry flour left. The batter will be very thin.
- Pour the batter into your prepared pan and give the pan a couple or sharp raps on the counter. Bake for 30-35 minutes, or until the center springs back when lightly touched. (You can also ue a toothpick test.) This cake bakes quickly.
- I let the cake cool for 15-20 minutes in the pan, then gently lift it out (using the parchment paper as handles) to a cooling rack. Let it cool completely on the rack. Note: the cake can be made the day before.
peanut butter filling
- Use electric beaters to cream the 4 Tbsp salted butter, softened, 2/3 cup creamy peanut butter *, and 1 Tbsp vanilla extract. Add the 2 cups powdered sugar and 7 Tbsp half and half, and beat until smooth and fluffy. Add a bit more half and half if your filling is too thick. Add extra salt to taste if needed.
assemble the cake
- Slice the cake in half crosswise and remove the parchment paper from the bottom. Place one half on your serving plate, flat side up.
- Spoon the peanut butter filling on the cake and gently spread out to the edges. There will be a generous amount!
- Place the second half of the cake on top of the filling, flat side down.
chocolate glaze
- Put the 1 cup dark or semi sweet chocolate with the 1/3 cup heavy cream and 2 Tbsp butter in a microwave safe bowl and microwave for one minute. Let sit for 2 minutes, then gently stir to melt the chocolate until the mixture is thick and glossy with no lumps.
- Let the glaze cool for a few minutes to thicken up, then gently pour the ganache over the top of the cake, nudging it towards the sides with the back of a spoon. It should just start to drip down the sides.
- Let the ganache set up before serving. Refrigerate the cake if not serving right away.
- To serve slice the cake into squares or rectangle slices. I like to slice the whole thing in half, and then slice each half. Any way you slice this cake, it's delicious ๐
Notes
- Use a creamy style peanut butter, and avoid natural style brands where the oil separates out from the nut butter.ย
Oh Lord – a mutant Funny Bone! I’m in trouble! ๐คค
Funny Bones were (are?) the best!
Do you think it would work to substitute a combo of heavy cream and milk (maybe 50/50?) for the half and half?
Yes, that will definitely work. You can also use buttermilk in the cake (but not the pb cream)