Prepare the coffee so it can cool. Preheat the oven to 350 degrees F and if making cupcakes, line the cups. This makes 30 large cupcakes, so tulip lines work great. If making a layer cake, prep three 9" round pans.
In a large bowl using a hand-held mixer or stand mixer fitted with a paddle attachment add the flour, sugar, baking powder, cocoa, soda, and salt and mix.
Add in the buttermilk, oil, coffee, eggs, and vanilla, and mix thoroughly.
Pour the batter into the pans and bake until a toothpick comes out clean about 22 minutes. Cool the cakes completely on a wire rack.