2/3 Cup unsalted butter, softened
¾ Cup sugar
¼ teaspoon salt
1 large egg, plus 3 egg yolks for painting
1 tablespoon milk
1 teaspoon pure vanilla extract
2 Cups sifted all-purpose flour, plus more for work surface
1 teaspoon baking powder
Red, Green and Yellow food coloring
In a large mixer bowl, beat butter on medium high speed 30 seconds. Add sugar and salt; beat, scraping down sides of bowl occasionally, until light and fluffy about 2 minutes. Add whole egg, milk and extract; beat until combined. Reduce speed to low; beat in flour and baking powder until combined.
Halve dough and wrap each piece well with plastic wrap. Refrigerate until firm, 2 to 3 hours.
Line two baking sheets with parchment paper; set aside. On lightly floured surface, roll out dough, one piece at a time, to 1/8 – inch thickness. Using 2-3 1/2 inch cookie cutters, cut into shapes and transfer to prepared sheets; keep chilled until ready to paint.
For egg yolk paint, divide yolks among 3 small bowls and stir just enough food coloring into each to achieve desired shades. Using a small, clean paintbrush, paint cutouts.
Heat oven to 375 degrees and place rack in center. Bake, one sheet at a time, until firm and light brown around edges, 7 to 8 minutes. Transfer sheets to wire racks and let cool completely.
**** Store in an airtight container at room temperature, in single layers separated by wax paper, up to 3 days******