Preheat oven to 350 degrees. Butter three 9-inch cake rounds. Dust with flour and tap out the excess.

Mix together flour, sugar, cocoa powder, baking soda, baking powder, and salt in a stand mixer using a low speed until combined.

Add eggs, buttermilk, warm water, oil, and vanilla. Beat on a medium speed until smooth. This should take just a couple minutes.

Divide batter among the three pans. Approx. just over 3 cups of batter to divide it evenly.

Bake for 30-35 minutes in a 350 degree oven until a toothpick inserted into the center comes out clean.

Cool on wire racks for 15 minutes, then turn out the cakes onto the racks and allow to cool completely.

For frosting: In a large bowl, beat together butter and cream cheese until fluffy. Use a hand mixer or stand mixer for best results.

Add in cocoa powder and vanilla extract. Beat until combined.

Beat in powdered sugar, 1 cup at a time. Add milk as necessary to make a spreadable consistency. The frosting should be very thick and will thicken even more if refrigerated.