Combine chocolate and 1 tablespoon butter in top of a double boiler; place over simmering water until melted. Remove from heat, and set aside.
Cream remaining butter in a large mixing bowl; gradually add 1 cup sugar, beating well. Add egg, coffee, and reserved chocolate mixture; beat well.
Combine flour, baking powder, and cinnamon in a medium mixing bowl; stir into creamed mixture, mixing well. Chill dough at least 2 hours.
Turn dough out onto a lightly floured surface; roll to 1/4-inch thickness. Cut with a floured doughnut cutter. Place 2 inches apart on lightly greased cookie sheets; sprinkle lightly with additional sugar. Bake at 350° for 12 minutes. Cool slightly on cookie sheets. Remove to wire racks to cool completely.