In a saucepan, combine 1/2 cup sugar and 1 tablespoon cocoa. Stir in boiling water until smooth. Simmer, uncovered, for 5 minutes. Meanwhile, in a bowl, cream butter, vanilla and remaining sugar. Combine flour, baking powder, salt and remaining cocoa; add to creamed mixture alternately with milk. Beat well. Pour the chocolate sauce into a greased 1-1/2-qt. baking dish. Drop batter by rounded teaspoonfuls onto sauce. Bake, uncovered, at 375° for 25 minutes or until a toothpick inserted in the center comes out clean. Serve warm with ice cream. Garnish with cherries if desired.