- Vegetable oil spray for misting the pan
- 1 package (18.25 ounces) plain devil’s food cake mix
- 2 tablespoons unsweetened cocoa powder
- 1 1/3 cups buttermilk
- ½ cup vegetable oil, such as canola, corn, safflower, soybean, or sunflower
- 3 large eggs
- 1 teaspoon pure vanilla extract
1. Place a rack in the center of the oven and preheat the oven to 350°F. Lightly mist a 13 by 9 inch baking pan with vegetable oil spray. Set the pan aside.
2. Place the cake mix, cocoa powder, buttermilk, oil, eggs, and vanilla in a large mixing bowl. Blend with an electric mixer on low speed for 1 minute. Stop the machine and scrape down the sides of the bowl with a rubber spatula. Increase the mixer speed to medium and beat 2 minutes more, scraping the sides down again if needed. The batter should look thick and combined. Pour the batter into the prepared pan, smoothing it out with the rubber spatula. Place the pan in the oven.
3. Bake the cake until it springs back when lightly pressed with your finger and just starts to pull away from the sides of the pan, 40 to 45 minutes. Remove the pan from the oven and place it on a wire rack to cool for 30 minutes.
4. Meanwhile, prepare the Peanut Butter Frosting .
5. Frost the top of the cake, spreading the frosting out to the edges with a rubber spatula. Slice and serve.
*Store this cake, covered in aluminum foil or plastic wrap, at room temperature for up to 3 days or in the refrigerator for up to 1 week. Or freeze it, wrapped in foil, for up to 6 months. Thaw the cake overnight on the counter before serving.