If you want a super-moist cupcake, then this is the one. I initially got this recipe from "Taste of Home" magazine, but after having tasting it at its original state; I decided to tweak it just a tad, and they turned out great!
In a large bowl, beat the eggs, coffee, oil, vinegar and vanilla until well blended. In a small bowl, combine the flour, sugar, baking soda and salt; gradually beat into coffee mixture until blended. Do not over mix (this will cause tough cupcakes).
Fill paper-lined muffin cups three-fourths full.(note: for cupcakes to all be the same size; use a 1/4-1/3 measuring cup to fill your cups). Bake at 350° for 20-25 minutes or until a toothpick comes out clean and the cupcakes are a rather light gold, and mildly fluffed. Cool for about 10 minutes outside of the pan (to avoid residule cooking) before frosting *as below* .
For frosting, in a microwave or over a saucepan, melt chocolate and butter; stir until smooth. Transfer to a large bowl. Gradually beat in confectioners' sugar and coffee at a high rate until smooth and holding (also, if the frosting seems a tad runny; add a sprinkle more confectioners sugar/ coocoa powder). Pipe frosting onto cupcakes. Top with chopped chocolate bits.