Vanilla Bean Peanut Butter Crunch Cake is the ultimate in delicious layer cakes. It’s full of peanut butter, white chocolate, and rice krispies, and yep, vanilla beans. It’s just full of bunches of my favorite ingredients.
It’s also full of emotions: love mixed with sadness and grief over missing my sweet Goldilocks. But love is the primary emotion in there because without my deep love for her I wouldn’t be feeling her loss so intensely. And were it not for that love this cake probably would never have happened. And I’m so glad it did happen because it’s delicious.
Eight years ago Friday, I signed my sweet Goldie’s adoption papers. She was a pound puppy and really scruffy, and had more energy in her tail than I have in my whole body. And she was perfect.
But because I got her at the pound I didn’t know her real birthday (which bothers me to this day); so we called her adoption day her birthday and every year I’d make a fancy cake for her. Actually the cake was for me because she (strangely) didn’t seem to know what a special day August 26th is. And, obviously, because she can’t have chocolate—while I need it by the bucket-full.
Even though Goldie passed away in March I wanted to continue the tradition of celebrating her. Hence the peanut butter buttercream. She loved peanut butter even more than I do.
And this cake is not for the casual peanut butter lover. The filling and frosting are both heavy with the stuff. The peanut butter buttercream tops a super-light, crazy-moist vanilla bean cake. But the best part is sandwiched between those cake layers; the filling is made with peanut butter, white chocolate, and rice krispies. When it sets up, it takes on a sort of frosting-like consistency. And the cereal’s crunch is SO PERFECT paired with the soft cake layers.
For a little extra crunch I sprinkled cocoa puffs on top of the frosted cake but that’s totally optional, as is the chocolate buttercream I decorated with. You could eliminate those elements completely or use cocoa krispies or crushed Oreos or anything you want. Go crazy! It’s your cake, after all.
And you will love it. For reals.
- 1 cup whole milk, at room temperature
- 1 teaspoon vanilla extract
- 2 vanilla beans
- 1 cup unsalted butter, at room temperature
- 2 cups granulated sugar
- 3 cups cake flour
- 1 tablespoon baking powder
- 1/2 teaspoon salt, divided
- 5 egg whites, at room temperature
- 3 1/2 cups smooth peanut butter (don’t use natural)
- 6 ounces white chocolate, finely chopped
- 1 tablespoon unsalted butter
- 5 cups Rice Krispies
- 12 tablespoons unsalted butter, at room temperature
- 1 cup smooth peanut butter (don’t use natural)
- 1 teaspoon vanilla extract
- 1/4 teaspoon salt
- 2 cups powdered sugar
- 1 tablespoon whole milk or heavy cream, as needed to thin frosting
- cocoa puffs for garnish, if desired
- 1/2 cup unsalted butter, at room temperature
- 1/2 teaspoon vanilla extract
- 1/4 teaspoon salt
- 5 tabespoons cocoa powder
- 1 1/2 cups powdered sugar
- 1 tablespoon milk or heavy cream, as needed
- Set oven rack in the middle position and preheat oven to 350 degrees. Spray three 9-inch round cake pans with cooking spray, then line the bottoms with parchment paper. Spray the parchment with cooking spray, then lightly dust with flour.
- Combine milk and vanilla extract in a 2-cup glass measuring cup. With a sharp knife, slice vanilla beans down the middle. Run the back of the knife over the vanilla beans to remove the seeds; add the seeds to the milk. Mix with a fork until well blended.
- Beat butter on medium speed in the bowl of a stand mixer fitted with the paddle attachment until creamy, about 2 minutes. Gradually add sugar, beating until light and fluffy, scraping down the sides of the bowl as needed.
- Sift together flour, baking powder, and 1/4 teaspoon salt in a medium mixing bowl. With mixer on low speed add 1/3 of the dry ingredients to the butter mixture, then half of the milk mixture. Mix until just blended. Add another 1/3 of the dry ingredients, then the remaining milk mixture, again mixing until just blended. Mix in remaining dry ingredients.
- Beat egg whites and remaining 1/4 teaspoon salt with an electric mixer on medium speed until stiff peaks form. Gently fold into the batter with a rubber spatula. Divide batter evenly between prepared cake pans and smooth the tops.
- Bake at 350 degrees for 20 to 23 minutes, until a toothpick inserted into the center of the cakes comes out clean. Cool cakes in pans for 10 minutes. Run a knife around the sides of the pan, then invert cakes onto a wire rack. Let cool completely before assembling the cake.
- Spray two 9-inch cake pans with cooking spray, line the bottoms with parchment paper, then spray parchment with cooking spray.
- Combine peanut butter, white chocolate, and butter in a large microwave-safe bowl. Heat in 30-second intervals, stirring after each interval, until chocolate is melted and mixture is smooth. Stir in Rice Krispies.
- Divide evenly between prepared cake pans and smooth the tops with a rubber spatula. Refrigerate until set, about 2 hours.
- In a stand mixer fitted with the paddle attachment, beat butter on medium speed until light and creamy, about 2 minutes. Add peanut butter and beat 1 minute more. Beat in vanilla and salt, then turn mixer to low and gradually add powdered sugar. Beat on high speed for 4 minutes. Add milk 1 teaspoon at a time to thin to a spreadable consistency, if necessary.
- Beat butter on medium speed until light and fluffy, about 2 minutes. Add vanilla and salt and beat to combine. Beat in cocoa powder, then turn mixer to low and gradually add powdered sugar. Beat on high speed for 4 minutes. Add milk 1 teaspoon at a time to achieve a pipe-able consistency.
- Run a knife around the edge of the cake pans and gently shake to remove filling layers. Spread a very thin layer of peanut butter buttercream on one cake layer, then place one filling layer on top. Spread another thin layer of peanut butter buttercream on top of the filling. Repeat with remaining filling and frosting layers. (Depending on how much your cake layers shrank in the oven, you may need to trim the filling layers. To trim, run a sharp knife around the outside of the cake, shaving pieces of filling down to the size of the cake.) Use remaining frosting to cover the top and sides of the cake.
- Pipe chocolate frosting along the top of the cake—or anywhere you wish. Sprinkle cocoa puffs on top, then press gently into cake. Serve and enjoy.
filling adapted from How Sweet Eats
peanut butter buttercream adapted from Food.com