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 thoroughly until uniform.
04 - Gradually add wet ingredients to dry ingredients, mixing until just combined. Avoid overmixing to prevent tough texture.
05 - Divide batter evenly between prepared pans. Bake for 28-32 minutes, until toothpick inserted in center comes out clean.
06 - Cool cakes in pans for 10 minutes, then turn out onto wire rack to cool completely before frosting.
07 - Beat cream cheese and butter in large bowl until smooth and creamy, about 2-3 minutes.
08 - Gradually add powdered sugar, vanilla, and salt. Beat until fluffy and well combined, scraping sides as needed.
09 - Place one cooled layer on serving plate. Spread with frosting. Top with second layer and frost top and sides evenly.
10 - Decorate as desired. Chill for at least 30 minutes before slicing for clean cuts.