Preheat oven to 350°F and spray two 8-inch round cake pans with nonstick cooking spray, or prepare with GOOP. Set aside.
Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into a large 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 the mixer still on low, add the coffee and mix just to combine. Scrape the bottom and sides of the bowl with a rubber spatula.
Equally pour the batter into the prepared pans and bake for 30 to 40 minutes, or until a cake tester or toothpick comes out mostly clean (not wet). Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.