Gluten-Free Sugar Cookies

Prepare the Dough:

1. Beat sugar and butter with a stand mixer fitted with a paddle attachment on medium speed until incorporated, about 3 minutes.

2. Add egg, egg yolk, milk, vanilla extract, and almond extract to butter mixture in mixer; beat on medium-low speed until combined, about 1 minute, stopping to scrape down sides of bowl as needed.

3. Whisk together flour, baking powder, salt, cinnamon, and nutmeg in a medium bowl. Slowly add flour mixture to butter mixture, beating on low speed until combined, about 1 minute, stopping to scrape down sides of bowl as needed. Place dough on plastic wrap, and wrap tightly, forming a rectangle about 1-inch thick. Refrigerate at least 12 hours or up to 2 days.
   

4. Preheat oven to 350°F. Line 2 large rimmed baking sheets with parchment paper. Unwrap dough, and place between 2 pieces of parchment paper. Roll out dough to about 1/4-inch thickness. Peel off top piece of parchment. Using 2- to 3-inch holiday cookie cutters, press out shapes, dipping cookie cutters in flour as needed to prevent sticking; place on prepared baking sheets, about 1/2-inch apart (about 22 per sheet). Reroll remaining dough using new parchment paper.

5. Bake 1 baking sheet of cookies at a time in preheated oven until cookies are set and edges are slightly brown, 10 to 12 minutes. Remove from oven, and let cool for 5 minutes on baking sheet;  transfer cookies to a wire rack, and let cool completely, about 15 minutes.

While cookies bake, prepare the Icing:

1. Whisk together egg whites, powdered sugar, vanilla extract, and lemon juice in a large bowl until combined; add food coloring (if using), stirring to combine. (If desired, add water, 1 teaspoon at a time, until desired spreading consistency.)

2. Place about 1 cup Icing into a disposable piping bag, and cut about a 1/8-inch hole from tip of bag. Line edges of cookies with Icing, and fill in top surface of cookies with Icing using a toothpick to spread Icing. Sprinkle with sparking sugar before Icing sets.