01 -
Preheat your oven to 350°F (175°C). Line a standard 12-cup muffin tin with paper cupcake liners.
02 -
In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt until well combined and free of lumps.
03 -
In a large bowl, whisk together the eggs, granulated sugar, vegetable oil, and vanilla extract until smooth and well blended.
04 -
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk. Begin and end with the dry ingredients (add ⅓ dry, then ½ buttermilk, then ⅓ dry, then remaining buttermilk, then remaining dry). Mix just until combined after each addition.
05 -
Slowly stir in the hot coffee (or hot water) until the batter is smooth. The batter will be quite thin, but this is normal.
06 -
Divide the batter evenly among the prepared cupcake liners, filling each about ⅔ full. Do not overfill.
07 -
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean or with just a few moist crumbs.
08 -
Remove from the oven and allow the cupcakes to cool in the muffin tin for 5 minutes. Then transfer them to a wire rack to cool completely before frosting.
09 -
Place the chocolate chips in a heatproof bowl. Heat the heavy cream in a small saucepan until hot but not boiling, then pour over the chocolate chips. Let sit for 2 minutes, then whisk until smooth and glossy. Set aside to cool to room temperature.
10 -
In a large bowl, beat the softened butter with an electric mixer until light and fluffy. Add the powdered sugar, vanilla extract, and pinch of salt. Beat on low speed until incorporated, then increase to medium-high and beat until smooth.
11 -
With the mixer on medium speed, gradually add the cooled chocolate mixture to the buttercream. Beat until well combined, smooth, and fudgy in texture.
12 -
Once the cupcakes are completely cooled, pipe or spread the frosting onto each cupcake. If the frosting is too soft, refrigerate it for 10-15 minutes before using.
13 -
If desired, decorate the frosted cupcakes with white chocolate chips, chocolate shavings, or other toppings of your choice.
14 -
Serve immediately or store in an airtight container. Frosted cupcakes can be kept at room temperature for 1-2 days or refrigerated for up to 5 days.