1-First, preheat your oven to 350 degrees Fahrenheit and line a muffin tin with cupcake liners to get started on this dark chocolate cupcakes recipe. In a small bowl, whisk together flour, cocoa powder, baking soda, and salt to ensure everything mixes evenly.

2-Next, in a medium bowl, whisk the egg, brown sugar, and sugar until they blend well. Add the milk, coffee, and melted butter to this mixture, whisking to combine all the wet ingredients smoothly. Then, gently add the dry ingredients to the wet ones and mix just until combined, avoiding overmixing to keep the cupcakes tender.

3-Divide the batter evenly into the 12 cupcake liners, filling each about three-quarters full for the best rise. Bake for 15 to 21 minutes, checking with a toothpick to see if it comes out clean or with a few moist crumbs. Once baked, cool the cupcakes in the pan for 10 minutes before moving them to a wire rack.

4-For the frosting, melt the chopped chocolate in the microwave, stirring every 15 to 30 seconds until smooth. Heat the cream until hot, mix it with the melted chocolate, and let it cool until just warm. Whisk in the butter until the frosting is smooth, then let it sit to reach a good consistency for spreading or piping.

5-Finally, frost the cupcakes using a piping bag with a 1M tip or a knife for a simple finish, and garnish with chocolate chips if you like. This step adds the rich touch that makes these dark chocolate cupcakes truly special.