For the Cake
Preheat your oven to 350°F (175°C). Grease and line two or three 9-inch round cake pans with parchment paper.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and cocoa powder.
In a separate bowl, combine buttermilk, melted butter, vegetable oil, eggs, vinegar, vanilla extract, and purple food coloring. Mix well.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Do not overmix.
Divide the batter evenly among the prepared cake pans. Smooth the tops with a spatula.
Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
For the Cream Cheese Frosting
Beat the cream cheese and butter together until smooth and creamy.
Gradually add powdered sugar, 1 cup at a time, mixing on low speed until fully incorporated.
Add vanilla extract and a pinch of salt. Beat on medium-high speed until light and fluffy.
Assembling the Cake
Place the first cake layer on a serving plate. Spread an even layer of frosting on top.
Repeat with the remaining layers, finishing with frosting on the top and sides of the cake.
Smooth the frosting with a spatula or create decorative swirls.
Step-by-Step Instructions
Prepare the Pans: Grease and line with parchment to prevent sticking.
Mix Dry and Wet Ingredients: Combine separately for even distribution.
Incorporate Food Coloring: Adjust the amount to achieve your desired shade of purple.
Bake and Cool: Allow the cake layers to cool completely before frosting.
Frost and Decorate: Layer and cover the cake with cream cheese frosting.