BEAT first 4 ingredients in large bowl with mixer until well blended. Add flour; mix well. Cover. Refrigerate several hours or overnight.
HEAT oven to 350°F. Roll out dough to 1/8-inch-thickness on lightly floured surface. Cut into shapes with 2-inch cookie cutters; sprinkle with colored sugar. Or, leave plain to frost later with decorating icing (after cookies are baked and cooled). Place on baking sheets.
BAKE 12 to 15 min. or until edges are lightly browned. Remove to wire racks. Cool completely.