Preheat the oven to 350 degrees and spray a bundt pan with nonstick cooking spray.
In a medium mixing bowl, sift together flour, sugar, baking soda, salt, and cocoa. Set aside.
In a large mixing bowl, add oil, buttermilk, eggs, food coloring, vinegar, and vanilla. Using an electric mixer, beat on medium, for 1 minute. Turn mixer to low and add flour mixture, about 1/2 cup at a time, and mix until each addition is just combined.
Pour batter into prepared bundt pan and bake in preheated oven 40-55 minutes (the original instructions called for 40 minutes of baking. Mine took 52 minutes) or until a cake tester or bamboo stick comes out with just a few moist crumbs. Cool completely before frosting.
Meanwhile, make frosting; In a medium mixing bowl, using an electric mixer, beat butter and cream cheese until just smooth and combined. Turn the mixer on low and add the powdered sugar slowly until frosting is smooth. Stir in vanilla.
Spread or pipe frosting over completely cooled cake. Store any leftovers in the fridge!