Preheat the oven to 350°F, and lightly grease a 7-inch cake pan. Set aside.
In a medium bowl, sift together the flour, cocoa powder, baking soda and salt.
½ cup cake flour, 1 teaspoon cocoa powder, ¼ teaspoon baking soda, ¼ teaspoon salt
In a separate medium bowl, use an electric mixer to cream together the butter and sugar until light and fluffy, about 3 minutes. Add the egg, and mix well to combine.
2 tablespoons unsalted butter, ½ cup granulated sugar, 1 large egg
Add the oil, vanilla, food coloring and vinegar to the butter mixture, and continue to mix on low speed just until combined.
1 tablespoon canola oil, 2 ½ teaspoons red food coloring, 1 teaspoon vanilla extract, ½ teaspoon white vinegar
Add half of the dry ingredients and half of the buttermilk to the wet ingredients. Beat on low speed, then repeat with the remaining dry and wet ingredients. Pour the batter into the prepared pan.
¼ cup buttermilk
Bake for 15-18 minutes or until a toothpick inserted in the center comes out clean. Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
For the Frosting:
In a medium bowl, use an electric mixer to beat the cream cheese, butter, powdered sugar, and vanilla until smooth and creamy. Use an icing spatula to apply the frosting to the cake in an even layer.
4 ounces block-style cream cheese, 4 tablespoons unsalted butter, ¾ cup powdered sugar, ½ teaspoon vanilla extract
Serve the cake immediately or refrigerate until ready to serve.
Scroll up and see the post for tips, answers to frequently asked questions, and storage information.
Notes
*The calories listed are an approximation based on the ingredients in the recipe card and a serving size of ⅙ of the cake. Actual calories will vary.*For more information, tips, and answers to frequently asked questions, please refer to the post.*The cake can also be made in a 6-inch cake pan. However, the bake time may need to be adjusted since the cake will be thicker. Add 3-5 additional minutes, check the cake, and add more time from there if needed.