Super Moist One-Layer Chocolate Cake
This incredibly moist one-layer chocolate cake is topped with the most luscious chocolate buttercream - aka it's perfect for a small gathering or a weekday treat.
Servings: 8 people
Ingredients
For the One-Layer Chocolate Cake
- 1 cup (200g) granulated sugar
- 1/4 cup vegetable oil
- 1 large egg at room temperature
- 1/3 cup sour cream at room temperature
- 1/4 cup whole milk at room temperature
- 2 tsp pure vanilla extract
- 1 tsp baking soda
- 1/2 tsp baking powder
- 1/2 tsp cream of tartar
- 1/2 tsp kosher salt
- 1/3 cup (34g) Dutch-process cocoa powder
- 1 cup (150g) all-purpose flour
- 1/2 cup freshly brewed hot coffee
For the Chocolate Cream Cheese Buttercream
- 3/4 cup unsalted butter at room temperature
- 4 oz cream cheese at room temperature
- 1/4 cup cocoa powder
- 1 tsp pure vanilla extract
- 1/8 tsp kosher salt
- 2 1/2 cups powdered sugar
- 1 Tbsp heavy cream
- 1 tsp instant coffee powder
Instructions
For the Chocolate Cake:
- Preheat oven to 350°F. Grease one 9-inch (or use an 8-inch pan, see not below) round cake pan with cooking spray, line the bottom with a parchment paper round, and grease again. Set aside.
- Add the granulated sugar, oil, and egg to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed 2 minutes or until well combined.
- Beat in the sour cream, milk, and vanilla until smooth.
- Add the baking soda, baking powder, cream of tartar, and salt, and beat on medium speed for 1 minute. Scrape down the sides of the bowl (we want to be sure the baking soda and baking powder are well incorporated into the batter).
- Beat in the cocoa powder until smooth. Next, beat in the flour on low speed until just combined. Do not over-mix here.
- With the mixer running on low speed, gradually add the hot coffee, mixing until just combined. Do not overmix! Scrape down the sides of the bowl and fold an additional few times by hand.
- Pour the batter into your prepared pan (this will be a very wet batter) and bake 25 to 30 minutes or until a toothpick inserted into the center of the cake comes out clean with a few moist crumbs. The cake should also spring back slightly when you press gently on the top.
- Cool the cake completely in the pan before turning it out onto a cooling rack, making sure it cools completely before you add the frosting.
For the Chocolate Cream Cheese Buttercream
- Beat the butter and cream cheese in a large bowl until fluffy, 2 to 3 minutes.
- Add the cocoa powder, vanilla, and salt, and beat until combined. Add the powdered sugar, 1 cup at a time, beating until light and fluffy.
- In a small bowl combine cream and instant coffee. Microwave 15 to 20 seconds, remove from microwave, and stir until coffee dissolves into the cream. Beat mixture into the buttercream until combined, adding additional heavy cream, if necessary, 1 Tbsp at a time, until desired consistency is reached.
- Spread the frosting over the cooled cake layer using a knife or offset spatula.
Notes
If you want to bake this cake in an 8-inch round cake pan, the baking time may need to increase by about 10 minutes. Just pay attention to the cake and make sure the cake tester comes out clean when inserted into the center of the cake.