To make the cookies:

1. In a large bowl, cream the butter and powdered sugar together with a mixer on medium speed until smooth, about 1 minute. Scrape the sides of the bowl and add the egg and extracts, beating on medium just until combined. Add the cake flour, cornstarch, cream of tartar, baking soda, baking powder, and salt. Stir on low just until combined and a dough comes together. Cover the bowl with plastic wrap and place in the fridge to chill until it comes to a play-doh consistency, about 1 hour. When ready to bake, preheat the oven to 375 degrees and line two baking sheets with parchment paper. Use a small cookie scoop or a spoon to portion out 1-1/2 teaspoon sized rounds of dough. Roll them in your hands briefly to smooth and place 2” apart on the prepared pans. Flour the flat bottom of a glass or measuring cup and gently press each round of dough down until it is just over ¼” thick. Bake in the oven until the edges and tops are barely set, about 7-8 minutes. Allow to cool completely prior to frosting. 

To make the frosting:

1. In a large bowl, cream the butter on medium speed until smooth and pale. About 2 minutes. Add the powdered sugar, salt, vanilla, almond extract, and 1 tablespoon of milk. Stir together on low until combined and then beat until smooth. Add additional milk to bring the frosting to your desired consistency. Add food coloring and spread on the cookies, adding sprinkles if desired.