Preheat oven to 350°F. Spray 2, 8-inch round cake pans with cooking spray.
Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into the bowl and mix until combined.
In another bowl, combine the buttermilk, oil, eggs, and vanilla.
With the mixer on low speed, slowly add the wet ingredients to the dry. With mixer still on low, add the coffee and stir just to combine, scraping the bottom of the bowl with a rubber spatula.
Pour the batter evenly into the two cake pans. Bake for 30-40 minutes, or until a cake tester or toothpick comes out mostly clean (not wet).
Let the cakes cool in the pans for 30 minutes. Then, turn them out onto a cooling rack to cool completely.