Preheat your oven to 350 degrees. Line two muffin tins with paper wrappers.
Whisk together the flour, baking soda, and salt in a small bowl.
In the bowl of an electric mixer cream the butter and brown sugar. Add the eggs, one at a time, followed by the vanilla and melted chocolate.
Stir in the dry ingredients and sour cream. Fold in the coffee.
Fill each cupcake liner 3/4 full. Bake 12-15 minutes or until a toothpick comes out clean.