Preheat oven to 350°F. Spray a 10-cup bundt pan with baking non-stick spray. Spray really well!
In a large mixing bowl, sift the flour and cocoa powder together. Add the sugar, baking soda, baking powder, and salt.
3 cups All-purpose flour, ¼ cup Unsweetened cocoa powder, 1 ¾ cups White granulated sugar, 1 teaspoon Baking soda, ½ teaspoon Baking powder, 1 teaspoon Salt
In a separate bowl, mix the oil, buttermilk, vinegar, eggs, vanilla, sour cream, and red food coloring. Mix until it is combined and bright red.
1 cup Oil, 1 ¼ cup Buttermilk, ¾ teaspoon White vinegar, 3 Large eggs, 2 teaspoon Pure vanilla extract, ¼ cup Sour cream, 1 ½ teaspoon Red food coloring
Pour the wet ingredients into the dry. Mix until just combined.
Pour batter into the bundt pan. For a 10- cup bundt pan use ⅞ of the batter. For a 12-cup bundt pan, use all of the batter.
Bake for 40-50 minutes. The cake is done baking when a toothpick inserted comes out clean. Let the cake sit in the pan for 10 minutes. Then, transfer to a cooling rack.
Allow cake to cool completely. Then, make the glaze.