1Heat oven to 375°F (350°F for dark or nonstick pans).
2In large bowl, stir together cookie mix, oil, water and eggs until soft dough forms.
3In bottom of ungreased 13x9-inch (3-quart) glass baking dish, press half of dough. Break chocolate bars into squares; arrange in rows on top of dough. Press remaining dough on top, covering chocolate bar squares.
4Bake 15 to 20 minutes or until golden brown. Cool completely, about 1 hour 30 minutes. For bars, cut into 6 rows by 4 rows.