Beat peanut butter, butter, brown sugar, granulated sugar and vanilla in large mixer bowl until creamy. Beat in eggs; flour. Stir in 3/4 cup chips. Spread into greased 13x9-inch baking pan.
Bake in preheated 350 degree oven for 20 to 25 minutes or until edges are lightly browned.
Remove from oven; immediately sprinkle with remaining chips. Let stand for 5 minutes, then spread the chocolate. Drop sprinkles candies over melted chocolate.
Cool in pan on wire rack. Makes about 2-1/2 dozen squares.