Bake 16 to 18 minutes or until very light brown (crust will be soft). Immediately sprinkle chopped chocolate evenly over hot bars. Let stand 5 minutes to soften; gently spread chocolate with spatula. Sprinkle with remaining 1/2 cup toffee bits. Refrigerate until set, about 1 hour. Cut into 6 rows by 4 rows. Store tightly covered at room temperature.