Preheat oven to 325°F. Mix flour and sugar in medium bowl; cut in butter until mixture resembles coarse crumbs. Stir in cereal.
Press cereal mixture firmly onto bottom of greased 13x9-inch baking pan; pierce dough lightly with fork.
Bake 20 min. or until lightly browned. Drizzle with melted chocolate. Cut into 32 bars while still warm. Makes 32 bars or 16 servings, 2 bars each.