Preparation:

1: Make the Cookie Dough

1. In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy, about 2-3 minutes.
2. Add the egg, vanilla extract, and almond extract (if using). Beat until well combined.
3. In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.
4. Gradually add the dry ingredients to the wet ingredients, mixing until a soft dough forms.
5. Divide the dough into two portions, flatten into disks, wrap in plastic wrap, and chill in the refrigerator for at least 1 hour.

2: Roll and Cut the Cookies

1. Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
2. On a lightly floured surface, roll out one portion of dough to about 1/4-inch thickness.
3. Use holiday-themed cookie cutters to cut out shapes like stars, trees, snowflakes, and stockings.
4. Place the cookies on the prepared baking sheets, spacing them 1 inch apart.

3: Bake the Cookies

1. Bake in the preheated oven for 8-10 minutes, or until the edges are just beginning to turn golden.
2. Allow the cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

4: Prepare the Royal Icing

1. In a medium bowl, whisk the powdered sugar, milk, and vanilla or almond extract until smooth. Adjust the consistency by adding more milk (for a thinner consistency) or more powdered sugar (for a thicker consistency).
2. Divide the icing into bowls and color with food coloring, if desired.
3. Transfer the icing to piping bags or squeeze bottles for decorating.

5: Decorate the Cookies

1. Use the royal icing to outline and flood the cookies. Add sprinkles, edible glitter, or additional decorations while the icing is still wet.
2. Let the decorated cookies sit at room temperature for at least 2 hours to allow the icing to set.