Preheat your oven to 325°F (162°C). Grease and flour two 9-inch round cake pans.
In a large mixing bowl, combine melted butter, vegetable oil, vanilla and sugar. Mix until well combined. Add eggs one at a time, beating well after each addition.
Add red gel food color until the desired shade of red is achieved. Add butter milk and mix until well combined.
In another bowl, mix together cake flour, baking powder, baking soda, salt, and cocoa powder.
Add the dry Ingredients to the wet Ingredients and mix just to combine.
Add vinegar at the end and beat until well combined.
Divide the batter evenly between the prepared cake pans. Smooth the tops with a spatula.
Bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely before frosting.