. Prepare the Dough:

1. In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
2. In a large bowl, beat butter and sugar with an electric mixer until light and fluffy, about 2-3 minutes.
3. Add the egg and vanilla extract, beating until combined.
4. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

2. Chill and Roll:

1. Divide the dough into two portions, flatten into discs, and wrap in plastic wrap. Chill for at least 1 hour.
2. Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
3. Roll out the dough on a lightly floured surface to about ¼-inch thickness. Cut out shapes using cookie cutters.

3. Bake:

1. Place cookies on the prepared baking sheets about 1 inch apart.
2. Bake for 8-10 minutes, or until edges are lightly golden. Allow to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

4. Decorate:

1. In a small bowl, whisk powdered sugar, milk, and vanilla until smooth. Add more milk for a thinner consistency if needed.
2. Divide the icing into separate bowls and tint with food coloring.
3. Decorate the cooled cookies using the icing and sprinkles. Allow the icing to set before serving.