Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.

In a medium bowl, whisk together flour, baking powder, and salt. Set aside.

In a large bowl, beat together the butter and granulated sugar until light and fluffy. Add in the egg, vanilla extract, and peppermint extract. Mix until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Divide the dough in half. Color one half with red food coloring, kneading until the color is even.

Roll out the plain and red dough separately to about 1/4 inch thickness. Layer one on top of the other and gently roll them together to form a log. Twist gently to create a swirl. Cut the dough into shapes using a tree cookie cutter.

Arrange cookies on the prepared baking sheet. Bake for 8-10 minutes, or until the edges are firm but not browned. Remove from oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

In a small bowl, mix powdered sugar, milk, and peppermint extract until smooth. Drizzle over the cooled cookies.

Add sprinkles or edible glitter while the glaze is still wet.