Peanut Butter Cup Ganche Cake

Today is my birthday.  I’m not really one for cake, so instead, I made myself some mint chocolate chip ice cream after noticing that my mint was growing out of control.  It’s funny; I had no problems at all with turning 30, but for some reason, 31 just seems so much older.  No, it’s not logical, and yes, I know 31 isn’t actually old.  Perhaps it’s because my lab is very graduate student heavy, and I spend most of my time with 23-year-olds.  Maybe it’s because so many of my friends had children this year and it’s hard for me to grasp that yes, we actually ARE old enough to have children.  Either way, no matter how old I’m feeling, I always get to remain a year younger than my husband and his friends.  It only seemed appropriate that I post a birthday cake on my birthday, even if it’s not for me – this was initially made for two of my husband’s closest friends, on account of their birthdays, and was an enormous hit.  chocolate peanut butter cup ganache cake IMG_6941 I’m not one for chocolate cake, but the peanut butter frosting?  Just give me a big bowl and a spoon, please.  The chocolate cake is light and fluffy, surrounded by thick layers of rich peanut butter frosting.  Warm chocolate ganache is then poured on top, dripping down over the sides.  Think it can’t get any better?  Go ahead and cover the top with chopped peanut butter cups.  Oh, did I forget to mention that there are more peanut butter cups between each layer of cake?  Yeah, that. This cake is truly a chocolate and peanut butter lover’s dream come true. chocolate peanut butter cup ganache cake IMG_6948 This is, without a doubt, the most requested cake that I have made.  I’ve made it for birthdays.  I’ve made it for anniversaries.  I made it for our neighborhood rotating dinner party, which led to a neighbor asking if I’d make it for her son’s first birthday party.  I’ve made it so much that I’m purposely taking a break and not making it for a while – there are other cake options out there, people!  How about a banana nutella cake?  Or carrot cake?  Maybe an oreo cakeFlourless chocolate cakeChocolate ganache bundt cake?  Or maybe even a candy cake – I haven’t made one of those in a while!  Better yet – ask me to make something I haven’t already posted on my blog, so I have an excuse to create and post a new recipe!  Oh fine, you want another peanut butter cup cake?  I can’t say no. chocolate peanut butter cup ganache cake IMG_7004 Chocolate Peanut Butter Ganache Cake
From Brown Eyed Baker Ingredients:

  • For the cake:
    • 2 1/2 cups plus 1 tablespoon all-purpose flour
    • 3 cups granulated sugar
    • 1 cup plus 1 tablespoon cocoa powder
    • 1 tablespoon baking soda
    • 1 1/2 teaspoon baking powder
    • 1 1/2 teaspoon salt
    • 3 eggs
    • 1 1/2 cups buttermilk
    • 1 1/2 cups coffee, hot
    • 3/4 cup vegetable oil
    • 4 1/2 teaspoons vanilla extract
  • For the peanut butter frosting:
    • 2 cups powdered sugar
    • 2 cups creamy peanut butter
    • 10 tablespoons unsalted butter, room temperature
    • 1 1/2 teaspoons vanilla extract
    • 1/2 teaspoon kosher salt
    • 2/3 cup heavy cream
  • For the chocolate ganache:
    • 8 ounces dark chocolate, chopped
    • 3/4 cup heavy cream
    • 30 miniature peanut butter cups, coarsely chopped, divided


  1. Preheat the oven to 350F.  Grease and flour three 8-inch round cake pans.
  2. Whisk together the eggs, buttermilk, coffee, oil, and vanilla, and set aside.
  3. Stir together the flour, sugar, cocoa powder, baking soda, baking powder, and salt in the bowl of a mixer.  Add the wet ingredients to the dry ingredients and mix until combined, about 2 minutes.  The batter will be quite thin.
  4. Divide the batter evenly among the three pans.  Bake for 30 minutes, or until a toothpick inserted into the center of the cake comes out almost clean.  Cool the cakes in the pan for 20 minutes, then turn out onto cooling racks to cool completely.
  5. To prepare the frosting, combine the powdered sugar, peanut butter, butter, vanilla, and salt in an electric mixer fitted with the paddle attachment.  Beat on medium-low speed until fluffy.  Add the heavy cream and beat on high speed until the frosting is light and smooth.
  6. To assemble the cake, level the cakes if necessary.  Cover the bottom layer of cake with 1 cup of the peanut butter frosting, and sprinkle 10 of the chopped peanut butter cups over the frosting.  Top with a second cake layer and cover with another cup of the frosting, followed by another 10 chopped peanut butter cups.  Place the final layer on top of the cake, face down, and frost with the remaining peanut butter frosting.  Refrigerate the cake for at least 1 hour, until the frosting is set.
  7. While the cake chills, prepare the chocolate ganache.  Place the cream in a small saucepan over medium heat and warm just until it comes to a boil.  Place the chopped chocolate in a glass mixing bowl or a 4-cup measuring cup, and pour the cream over the chocolate.  Allow this mixture to sit for 2 minutes to melt the chocolate, and then whisk from the center outside until the ganache is smooth.  Set aside to cool, whisking occasionally, until the ganache has thickened but is still pourable.
  8. Slowly pour the chocolate ganache into the center of the cake, allowing it to push itself outward and flow down the sides of the cake.  Top with the remaining chopped peanut butter cups.  Refrigerate until the ganache is set, at least 30 minutes.