Preheat oven to 350 degrees. Line standard size muffin pan with muffin cup liners.
Brew coffee. Dissolve instant espresso in hot coffee. Set aside.
In a medium bowl, whisk together buttermilk, oil, vanilla, and eggs with the sugars.
In a large bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt.
Add wet ingredients to the dry ingredients, alternating with the coffee and stir until just combined; do not overmix. The batter will be thin.
Using a medium cookie scoop, place ¼ cup of batter in each cupcake liner, filling them about ⅔ full.
Bake at 350 degrees for 18-22 minutes, turning your pans around halfway through. They are done when a toothpick or skewer inserted in the center comes out almost completely clean. Cool the cupcakes in the pan for 5 minutes, then remove from the pan and let cool completely on a cooling rack.