• Preheat oven to 350°F. Place the oven rack in the middle of the oven. Using nonstick cooking spray that contains flour, generously spray 3 — 6 inch cake pans. Set aside.
• In the bowl of a stand mixer whisk the cake flour, sugar, cocoa powder, baking soda, and salt. 
• In a separate bowl, or large liquid measuring cup, whisk the vegetable oil, sour cream, buttermilk, egg, vanilla extract, white vinegar, and black food coloring. Add the wet ingredients to the dry ingredients (using a paddle attachment) and mix on low until ingredients are combined. 
• Pour the batter into the three cake pans, use an off set spatula to spread the batter into an even layer. Tip: use a kitchen scale to ensure equal amounts of batter in each pan.
• Place the cake pans in the oven and bake for 25-28 minutes. The cake is done when a toothpick inserted in the center comes out with a few moist crumbs but no wet batter. (The cake will be more moist if you don't over bake it, so I like to remove it when the toothpick has moist crumbs on it– but no wet batter). Remove from the oven and let the cakes cool in the pan for 10 minutes before turning out onto a wire rack to cool to room temperature.
• Once cool, use a serrated knife to level off the domed tops of each cake layer. (If needed).

Black Cream Cheese Frosting

• Beat the butter and cream cheese in a stand mixer until smooth and creamy about 2-3 minutes. Add the powdered sugar 1 cup at a time. Mix in the black cocoa powder, vanilla extract and black gel coloring, about 2-3 drops. Whip until smooth. Add a splash of heavy cream if needed, to get desired consistency. 

Assembly

• Place 1 cake layer on a cake stand or cake plate. I like to put a small dollop of frosting on the cake stand to ensure the cake layer doesn’t move as I’m frosting it. 
• Place a heaping amount of frosting on top of the cake layer (about 1 cup). Gently pushing the frosting toward the cake edges with a spatula. Try to keep the frosting level. 
• Place the next cake layer on top of the frosting, doing your best to align the edges. Gently press the cake layer in place. Add about 1 cup of frosting to the top of the cake layer. Gently pushing the frosting toward the cake edges with a spatula. Try to keep the frosting level. Add the final cake layer on top. 
• Add a thin layer of frosting to the top and sides of the cake (this is called a crumb coat). Refrigerate the cake for 10 minutes to set the frosting (this prevents the crumbs from getting into your final frosting layer). 
• Lastly, apply a thick layer of frosting over the crumb coat, frosting the top and sides in an even layer.