Cream butter in a large mixing bowl; gradually add 2 cups sugar, beating until light and fluffy. Add cereal and vanilla, mixing well; add flour, mixing until well blended.
Shape into 1 1/2-inch balls; drop onto waxed paper that has been sprinkled with additional sugar.
Place balls, sugar-coated side down, 2 inches apart on ungreased cookie sheets. Gently press cookies with a fork in a crisscross pattern. Bake at 350° for 15 minutes. Remove from cookie sheets, and cool on wire racks.