Stir Bisquick mix, milk, sugar and butter until soft dough forms. Drop by 6 spoonfuls onto ungreased cookie sheet.
Bake 10 to 12 minutes or until golden brown. Split warm shortcakes; fill and top with strawberries and whipped topping. (Sweeten strawberries before making shortcakes so sugar has time to dissolve; for each quart of sliced strawberries, stir in 1/2 cup sugar.).