2. In large mixing bowl, beat together butter, sugar, egg yolks, lemon peel and vanilla until well combined. Add flour mixture, mixing well. Portion and shape dough into 1-inch balls. Roll in KELLOGG'S CORN FLAKES cereal. Place on ungreased baking sheets, about 2 inches apart. Flatten slightly.
3. Bake at 375°F about 8 minutes or until edges are lightly browned. Remove from baking sheets and cool on wire racks. Store in airtight container.