German chocolate cupcakes are an offshoot of classic German chocolate cake. They consist of chunks of bittersweet chocolate (although you can semisweet if you prefer), coffee, butter, cake flour, cocoa powder (for extra chocolate-y goodness) and buttermilk, among other things. However, the one thing that make them German chocolate, and not just standard chocolate cupcakes, is the semi-sweetened coconut flakes that are added to the chocolate frosting. Make sure to toast them first, in order to end up a very authentic treat!
Source David Lebovitz