Preheat the oven to 350º F. Add the butter and sugar to a stand mixer and beat for 3 minutes, or until it becomes light and fluffy.
Scrape down the sides of the bowl. Then add the egg, vanilla and almond extract and mix until fully incorporated.
In a separate bowl, mix the flour, baking powder and salt together. Then, add it to the bowl of the stand mixer and mix until it forms a loose dough.
Place the dough onto a clean surface and knead it until it forms a ball. If the dough is sticky, you can lightly flour the surface and your hands (I didn’t use any flour). Then, cut the dough into two even sections. Add blue food coloring to one half of the dough and green to the other. Knead the dough until the color is fully incorporated.
Take a piece of blue dough and a piece of green dough, and squeeze it together a few times until the colors are slightly marbled. Roll the dough into a ball, then flatten it to 1/4″ thick. Place it onto a cookie sheet lined with parchment paper or silpat, and repeat until all the dough is used up. Make sure to place the cookies at least an inch apart.
Bake for 6-8 minutes. Let them sit on the cookie sheet for a few minutes, until they are firm enough to move to a cooling rack. Once they are fully cooled, store them in an airtight container. Enjoy!