Place phyllo on cutting board; slightly butter the top. Repeat process with remaining phyllo dough. Cut dough into pieces large enough to wrap a banana in, then brush butter over the top of the dough pieces. Sprinkle chocolate mixture over the dough. Roll each banana in a sheet of dough. Place bananas on a sheet pan. Brush butter over the top of the dough. Sift powdered sugar over the bananas. Bake bananas in a 500 degree F oven until golden brown. Cut off the ends of the bananas before serving.
