• In a large bowl, cream butter, cream cheese, and sugar until light and fluffy.
• Beat in egg yolks and vanilla.
• Gradually beat in flour (½ cup at a time).
• Cover bowl with plastic wrap and refrigerate for at least 2 hours.
• Preheat oven to 350° and grease cookie sheets.
• On lightly floured surface, roll dough to ¼ inch thickness.
• Cut with cookie cutters.
• Place at least 1 inch apart on greased cookie sheets.
• Bake until firm but not brown, 10-12 minutes.
• Cool on cookie sheet for 5 minutes.
• Remove from cookie sheet and cool on wire rack.

Icing

• Beat butter, shortening, and vanilla until combined.
• Beat in powdered sugar.
• Add milk 1 tablespoon at a time until spreading consistency is reached.
• Beat until light and fluffy.
• Add food coloring (optional).