Preheat oven to 350-degrees.
In a medium-sized bowl, combine flour, cornstarch, and salt. Stir until well combined.
Cut COLD butter into cubes (they don't need to be perfect) and add to the bowl of a stand mixer (or in a large mixing bowl if you are using a hand mixer).
Add sugar and mix together until smooth and fluffy, scraping down the sides of the bowl if needed.
Add 1 egg, vanilla extract, and almond extract and mix until well combined.
Add the flour/cornstarch mixture in and mix on low speed until crumbles form (if you are at a higher elevation and the crumbles seem a little too dry you can add a tablespoon or two of water--not too much though, you want it to be crumbly, not sticky).
Remove crumbles from mixer and knead into a ball. Place between two pieces of parchment paper and roll out to about 3/8-1/2" thickness (however thick you want the cookies to be is how thick you want to roll it out-- these cookies aren't going to rise very much, if at all).
Use Christmas cookie cutters to cut shapes out of the dough. Place cookies on a baking sheet lined with a baking mat or parchment paper.
Bake for 10-12 minutes. Allow to cool COMPLETELY before icing with royal icing or cream cheese frosting, (see links below for icing/frosting recipes)