• Preheat the oven to 350 F. Spray 3 (8-inch) round pans or 2 (8- or 9-inch) round pans with cooking spray and line with parchment paper. Set aside.
  Cooking spray
• Combine the flour, cocoa powder, salt, and baking soda; mix with a whisk to blend and set aside.
  2 1/2 cups all-purpose flour | 1/4 cup unsweetened cocoa powder | 1/2 tsp fine salt | 1 tsp baking soda
• In a mixing bowl with an electric mixer, beat the butter until smooth and creamy. Add the granulated and brown sugars and beat on low speed until well blended.
  1/2 cup unsalted butter | 1 cup granulated sugar | 3/4 cup brown sugar
• Add the eggs and beat until blended.
  2 large eggs
• Add the vegetable oil, vanilla, vinegar, and food coloring; mix until blended. Add more food coloring, if needed, to reach the desired color.
  3/4 cup vegetable oil | 1 tbsp vanilla extract | 2 tsp vinegar | 1 to 2 tsp red food coloring gel
• Add 1/3 of the dry ingredients and 1/2 of the buttermilk; mix well. Repeat with the remaining 1/3 of the dry ingredients and the remaining buttermilk, mixing well. Add the remaining dry ingredients and beat just until smooth and well blended.
  1 cup buttermilk
  
• Divide the batter evenly among the 3 pans (or 2 pans) and spread evenly with an offset spatula.
• Bake the layers in the preheated oven for 25 to 30 minutes, until the cake bounces back when lightly touched with a finger.
• Cool the cakes in the pans on a rack for about 20 minutes. Remove them from the pan and cool completely on racks before frosting and assembling the layers.

Prepare the Frosting and Assemble the Cake

• In a mixing bowl with an electric mixer, beat the cream cheese until smooth. Add the butter and fine salt and beat until well combined.
  16 ounces cream cheese | 1/2 cup unsalted butter | 1/4 tsp fine salt
• Add 4 cups of confectioners' sugar and beat on low speed until well blended. Add more confectioners' sugar if a thicker frosting is desired, then beat in the vanilla extract. Continue beating for 1 to 2 minutes, until smooth and creamy.
  4 to 5 cups confectioners' sugar | 1 1/2 tsp vanilla extract