Heat oven to 375°F. In ungreased 13x9-inch pan, break up cookie dough. With floured fingers, press dough evenly in bottom of pan to form crust. Bake 12 to 15 minutes or until golden brown.
Arrange candy evenly over crust.
Bake 3 to 4 minutes longer or until candy softens. Meanwhile, in small bowl, mix cereal and walnuts.
With spatula or knife, quickly spread candy evenly over crust. Sprinkle evenly with cereal mixture; press in slightly. Cool completely, about 30 minutes. For bars, cut into 6 rows by 6 rows.