Combine sugar, margarine, and coffee granules in a small saucepan. Place over low heat; cook for 4 minutes or until margarine melts and the mixture is smooth, stirring frequently.
Combine sugar mixture, vanilla, egg whites, and egg; beat at low speed of a mixer until smooth.
Combine flour, baking powder, and salt; gradually add to creamed mixture, beating well. Stir in chocolate morsels. Spread batter into a 13 x 9-inch baking pan coated with cooking spray. Bake at 350° for 18 minutes; let cool in pan.