Chocolate Salted Peanut Butter Cake

Chocolate Salted Peanut Butter Cake by Rumbly in my TumblyMy little brother turned 34 last week.  Gone are the carefree days of sitting around in Grandma’s front yard with his shirt off and his sister’s sunglasses on.

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly

He and his fiancee have a restaurant they love that makes a chocolate cake with salted peanut butter frosting that they are always raving about.  Sounds good, yes?  I wanted to make a cake for my brother’s birthday dinner so I decided to try my hand at that particular cake, but it’s a small, local place and there was no recipe to be found so I had to wing it.

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly

As a general rule, I kind of suck at cakes.  I can make good cake. I can make good frosting.  I just lack the patience to enjoy the act of leveling them, filling them, frosting them, decorating them.  This cake was simple to frost and decorate and is one of the best cakes I’ve ever made or tasted.

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly

The chocolate cake is rich, fudgy, and incredibly moist.  The peanut butter frosting is perfect- sweet with that little bit of saltiness at the end. It’s so very rich that you can only have a very small slice.  The only thing that might have made this better would have been a sprinkling of chopped up peanut butter cups on top of the ganache, but that might be a bit too much even for me.

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly

Pro tip: For the ultimate moistness, make these cakes the day before, wrap each layer tightly in plastic wrap and then in foil, freeze them, and then take them out in the morning and thaw them slightly, level them, fill them, and the frost.  Keeps them super duper fudgy and moist.

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly

Recipe adapted from Smitten Kitchen and Smells Like Home

Chocolate Salted Peanut Butter Cake by Rumbly in my Tumbly


For the cake:
    • 2 cups all-purpose flour
    • 2 1/2 cups sugar
    • 3/4 cup unsweetened cocoa powder
    • 2 tsp baking soda
    • 1 tsp salt
    • 1 cup neutral vegetable oil
    • 1 cup sour cream
    • 1 1/2 cups brewed coffee
    • 2 tbsp distilled white vinegar
    • 1 tsp vanilla extract
    • 2 eggs
For the peanut butter frosting:
    • 2 cups creamy peanut butter
    • 4 cups powdered sugar
    • 1 cup plus 2 tbsp unsalted butter, at room temperature
    • 1 tbsp plus 1 1/2 tsp pure vanilla extract
    • 3/4 tsp Kosher salt
    • 1/2 cup heavy whipping cream
For the chocolate-peanut butter ganache:
  • 8 oz semisweet chocolate, coarsely chopped
  • 3 tbsp smooth peanut butter
  • 2 tbsp light corn syrup
  • 1/2 cup heavy whipping cream


  1. To make the cake: Preheat the oven to 350° F. Grease three 8-inch round cake pans with butter or baking spray. Line the bottom of each pan with a round of parchment paper and lightly grease the paper.
  2. In a very large bowl, sift the flour, sugar, cocoa powder, baking soda, and salt. Whisk to combine them well. Add the oil and sour cream and whisk to blend. Gradually beat in the coffee – splashing may occur if you add it too quickly. Blend in the vinegar and vanilla. Whisk in the eggs and beat until well blended. Scrape down the sides and bottom of the bowl and be sure the batter is well-mixed and no flour bits remain. Divide among the 3 prepared cake pans.
  3. Bake for 25 to 35 minutes on the same rack, if possible, without the cake pans touching each other, or until a cake tester or wooden toothpick inserted in the center comes out almost clean.(Don’t overbake!! Start testing at 25 mins and as soon as that toothpick comes out with little moist bits on it, pull the cakes out of the oven!)  Let cool in the pans for about 20 minutes. Invert onto wire racks, carefully peel off the paper liners, and let cool completely. (*If you’re using my freezing tip, wrap them in plastic wrap while they are still warm (but not hot), then foil, and stick them in the freezer still warm)
  4. To make the frosting: In the bowl of a stand mixer fitted with the paddle attachment, place the peanut butter and butter. Sift the sugar into the bowl. Add the vanilla extract and salt. Starting on low and gradually increasing (to prevent the sugar from covering your kitchen) the speed to medium-high, beat the ingredients until light and fluffy, scraping the sides and bottom of the bowl as needed, about 3-4 minutes. Beat in the heavy whipping cream.
  5. To frost the cake: Place one layer, flat side up, on a cake stand, cardboard cake round, or large serving plate. Spread 2/3 cup of the peanut butter frosting evenly over the top. Repeat with the next layer. Place the last layer on top and frost the top and sides of the cake with a scant amount of frosting to make a crumb coat to keep the crumbs from popping through the final frosting. You’ll need just enough to lightly cover the cake – there’s no need to be neat here. Let the cake chill for 15 to 30 minutes until firm, then use the remainder of the frosting to create a smooth final coating. Once the cake is fully frosted, chill the cake again and let it firm up before covering it with the ganache.
  6. To make the ganache: In the in a medium bowl set over a saucepan of simmering water, combine the chocolate, peanut butter, and corn syrup. Cook, whisking often, until the chocolate is melted and the mixture is smooth. Remove from the heat and whisk in the cream, beating until smooth. Use while still warm.
  7. To decorate with the ganache: Gently pour the ganache over the top of the cake, and using an offset spatula, spread it evenly over the top just to the edges so that it runs down the sides of the cake in long drips. Sprinkle the top with a tiny bit of sea salt.  Refrigerate, uncovered, for at least 30 minutes to allow the ganache to set completely. Take the cake out of the fridge about 1 hour before serving – it will be difficult to cut through the ganache if it is too cold.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s