Line 8- or 9-inch square pan with wax paper. Sprinkle 1-1/2 cups of the cereal evenly onto bottom of pan.
Spoon ice cream over cereal; smooth top with spatula, gently pressing ice cream into cereal on bottom of pan. Sprinkle with remaining 1-1/2 cups cereal; press with spatula into ice cream layer to secure.
Freeze 2 hours or until firm. Cut into 9 squares. Store leftover squares in freezer.