Preheat oven to 375°. Line cupcake pan with brown paper liners.
In the large bowl, sift flour, sugar, cocoa powder, baking soda, baking powder, and salt. Set aside.
In a medium bowl or large measuring cup, combine buttermilk, coffee, oil, egg and vanilla.
Add liquid mixture to dry ingredients and whisk until smooth, about 1 minute.
Divide batter among liners filling each about 1/2 – 2/3 full.
Bake until a wooden pick inserted into the center of the cupcake comes out clean, about 15-18 minutes.
Let cupcakes cool in pan for about 10 minutes. Transfer to wire rack to cool completely.
TIP: Try a test cupcake before baking the entire batch. If it overflows, increase your oven temperature by 25º. The increase in heat will help these delicate cupcakes rise faster reducing the risk of overflowing batter.