Step 1

For the cookies: Beat the shortening, granulated sugar, orange zest and vanilla in a large bowl with a mixer on medium speed until thoroughly combined, 2 to 3 minutes. Beat in the egg until light and fluffy, then beat in the milk.

Step 2

Sift the flour, baking powder and salt into a medium bowl. With the mixer on low speed, beat the flour mixture into the butter mixture until just combined. Divide the dough in half; flatten each half between 2 sheets of parchment or wax paper, wrap and refrigerate for at least 1 hour or freeze for 20 minutes.

Step 3

For the glaze: Whisk the egg yolk, water and food coloring in a small bowl until well combined.

Step 4

Preheat the oven to 375 ̊. Line 2 baking sheets with parchment paper. Roll out 1 piece of dough on a lightly floured surface until about 1/4 inch thick. Cut into stars or other shapes with 2- to 3-inch cookie cutters. Arrange the cookies about 2 inches apart on the prepared pans. Brush the tops with the egg yolk glaze.

Step 5

Bake the cookies until set but not browned, about 6 minutes. Let cool 3 minutes on the pan, then remove to racks to cool completely. Decorate with royal icing and sanding sugar. Let set about 1 hour.