Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans. Line with parchment paper and dust with flour for easy release.
In a large bowl, sift together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
In another bowl, cream the butter with the granulated sugar until light and fluffy. Add the vegetable oil and continue mixing. Add the eggs, one at a time, beating well after each addition. Mix in the vanilla extract and red food coloring until fully combined.
Alternate adding the dry mixture and buttermilk to the wet ingredients in 2–3 batches. Mix just until combined. Stir in the distilled white vinegar.
Divide the batter evenly between prepared pans. Bake for 25–30 minutes until a toothpick comes out clean from the center.
Let cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely.
Beat the cream cheese and butter until smooth. Gradually add the powdered sugar, mixing until smooth and fluffy. Mix in the vanilla extract. For lighter texture, add a splash of milk if desired.
Place one cake layer on a serving plate. Spread frosting evenly on top. Add the second layer, frost the top and sides generously. Optional: Decorate with crushed pecans, white chocolate shavings, or red velvet cake crumbs.
