In large bowl combine sugars, butter, cream cheese, salt, extracts and egg yolk; blend well. Stir in flour until well blended. Chill dough for 2 hours. Pre-heat oven to 375 F. On lightly floured surface, roll out dough, one-third at a time to 1/8″ thickness. Cut using your favorite lightly floured cookie cutter. Place 1″ apart on ungreased cookie sheet. Leave cookie plain, or brush with lightly beaten egg white and sprinkle with colored sugar. Bake for 7-10 minutes or until light golden brown. Cool completely on wire racks.