01 - Preheat oven to 350°F. Grease and line two 9-inch round cake pans with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking soda, salt, and cocoa powder until well blended.
03 - In a separate bowl, combine oil, buttermilk, eggs, food coloring, vanilla, and vinegar. Mix until fully incorporated.
04 - Gradually add wet ingredients to dry ingredients, mixing until just combined. Do not overmix to maintain cake texture.
05 - Divide batter evenly between the prepared cake pans, smoothing tops with a spatula.
06 - Bake for 28 to 32 minutes, or until a toothpick inserted in the center comes out clean.
07 - Let cakes cool in pans for 10 minutes, then carefully turn out onto a wire rack to cool completely.
08 - In a large bowl, beat cream cheese and butter until smooth and creamy using an electric mixer.
09 - Gradually add powdered sugar, vanilla, and salt. Beat until fluffy and well combined.
10 - Place one cooled cake layer on a serving plate. Spread with frosting. Top with second layer and frost the top and sides evenly.
11 - Decorate as desired and refrigerate for at least 30 minutes before slicing for clean cuts and best flavor.