Ultra-moist, deeply chocolate cupcakes made with oil, natural cocoa, and tangy buttermilk for a tender crumb. Exceptional with a tall swirl of chocolate buttercream and sprinkles.
Preheat the oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners and line a second pan with 2 liners. Set aside.
In a large bowl, whisk together the flour, cocoa powder, espresso powder, baking powder, baking soda, and salt until thoroughly combined.
In a medium bowl, whisk the eggs, granulated sugar, brown sugar, oil, and vanilla until completely smooth.
Pour half of the wet mixture into the dry ingredients, then add half of the buttermilk. Gently whisk for a few seconds. Repeat with the remaining wet ingredients and buttermilk, stirring just until combined. Do not overmix; the batter will be thin.
Divide the batter between liners, filling each only halfway full (this is imperative to prevent overflow and sinking).
Bake for 18–21 minutes, or until a toothpick inserted in the center comes out clean. Allow cupcakes to cool completely.
Frost cooled cupcakes with chocolate buttercream and decorate with sprinkles as desired. Store leftovers covered in the refrigerator for up to 3 days.