Beat peanut butter, butter, brown sugar, granulated sugar and vanilla in large mixer bowl until creamy. Beat in eggs; beat in flour. Stir in 3/4 cup morsels. Spread into greased 13 x 9-inch baking pan.
Bake in preheated 350� F. oven for 20 to 25 minutes or until edges are lightly browned. Remove from oven; immediately sprinkle with remaining morsels. Let stand for 5 minutes; spread. Sprinkle colored sugar over melted chocolate. Cool in pan on wire rack.