Heat oven to 350°. Cream shortening and confectioner sugar. Blend in 1 1/2 cups flour.
Press evenly in bottom of ungreased 9x13x2 inch baking pan. Bake 12-15 minutes. Mix remaining ingredients; spread over hot baked layer and bake 20 minutes longer.
Combine icing ingredients and spread over warm bars. Cool; cut into bars 3×1 inch.