1Heat oven to 350°F. Lightly spray 2 large cookie sheets with cooking spray.
2In large bowl stir cookie mix, butter, egg, water and vanilla until soft dough forms. Cover, and refrigerate until firm; about 30 minutes.
3Divide dough in half. Stir melted chocolate into 1 half of dough. Shape about 1/2 teaspoon each of chocolate and white dough into 1-inch ball of marbled dough. Place about 1 inch apart on prepared cookie sheet. Press bottom of glass into dough to grease, then dip into granulated sugar; press on shaped dough until about 1/4 inch thick.
4Bake 8 to 11 minutes or until set and edges just begin to brown. Cool 1 minute; remove from cookie sheets to wire rack.