PREHEAT oven to 350°F.
BEAT butter and sugar in large bowl with electric mixer on medium speed until light and fluffy. Add egg yolk; beat until well blended.
ADD flour; stir until well blended. Stir in 1 cup of the cereal.
ROLL level tablespoonfuls of dough into balls; place on ungreased baking sheets 1/2-1 inch apart. Flatten cookies. With fingertip, make 3 indents on one side of each cookie for "paw print".
BAKE at 350°F for 12 minutes or until lightly browned. (Do not overbake). Cool a few minutes on wire cooling rack.
FILL "paw print" indents evenly with melted chocolate; top each print with 1 piece of cereal. Cool completely.
