In a large bowl, combine 1-1/2 cups flour, sugar, yeast and salt. Add water and shortening. Beat on medium speed for 3 minutes. Stir in remaining flour (batter will be stiff). Do not knead. Cover and let rise in a warm place for 30 minutes.
Stir dough down. Spread evenly into a greased 13-in. x 9-in. baking pan. Cover and let rise until doubled, about 40 minutes.
Bake at 375° for 30-35 minutes or until golden brown. Cool for 10 minutes before removing from pan to a wire rack. Brush with melted butter. Cut into squares.