Making the Cupcakes:

1. Preheat and Prep: Preheat the oven to 350°F (175°C) and line a cupcake pan with paper liners.
2. Mix the Dry Ingredients: In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
3. Combine Wet Ingredients: In a large bowl, whisk together the melted butter and sugar until smooth. Add the eggs one at a time, then mix in the vanilla extract.
4. Alternate Mixing: Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk. Stir until just combined.
5. Add Liquid & Chocolate Chips: Pour in the hot coffee (or hot water) and mix until the batter is smooth. Gently fold in the chocolate chips.
6. Fill and Bake: Divide the batter evenly among the cupcake liners, filling each about 2/3 full. Bake for 18-22 minutes or until a toothpick inserted in the center comes out clean.
7. Cool Completely: Allow the cupcakes to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

Making the Frosting:

1. Beat the Butter: In a large bowl, beat the softened butter until creamy and fluffy.
2. Add Cocoa and Sugar: Gradually mix in the powdered sugar and cocoa powder until combined.
3. Incorporate Vanilla & Cream: Add vanilla extract and 3 tablespoons of heavy cream. Beat for about 2 minutes until smooth and fluffy. If needed, add an extra tablespoon of cream to reach the desired consistency.
4. Frost the Cupcakes: Once the cupcakes are completely cool, frost them using a piping bag or a spatula.