Make the cookies:

1. In a large mixing bowl, whisk together flour, cornstarch, baking powder, baking soda, and salt. Set aside.
2. In another large mixing bowl, use an electric mixer (or in the bowl of a stand mixer fitted with the paddle attachment), to beat together butter, sour cream, and sugar on medium speed until light and fluffy, about 2 minutes. 
3. Add the eggs, vanilla extract, and almond extract, and beat until combined.
4. Gradually add the dry ingredients and beat until just combined. The dough will be soft and sticky.
5. Transfer the cookie dough to a sheet of plastic cling wrap and shape it into a disc. Wrap tightly and chill in the fridge until firm, at least 1 hour).
6. Preheat oven to 350 F. Line 2 large baking sheets with parchment paper or a silicone baking mat. Set aside.
7. Remove the dough from the refrigerator and transfer to a lightly floured surface. Use a rolling pin to roll the dough out to 1/2-inch thick. Use a round 2-inch cookie cutter to cut out circles.
8. Transfer the cookies to the lined cookie sheet, placing them 1-inch apart. Re-roll any scraps and repeat to cut out more cookies. Place the cookies in the fridge while the oven preheats.
9. Bake for 8-10 minutes until the edges just start to brown. The cookies will be light and pale. Do not overbake. Allow cookies to chill on the baking sheet for 10 minutes, then carefully transfer them to a wire cooling rack to cool completely.

Make the frosting:

1. In a medium mixing bowl, beat butter until light and fluffy, about 3 minutes. Add confectioners’ sugar and continue to beat until combined.
2. Add vanilla extract and 1 tablespoon of milk and beat until incorporated. If the frosting is too thick, add a teaspoon of milk at a time until desired consistency is reached.
3. Add pink food coloring and beat to incorporate.
4. Top the completely cooled cookies with a thin layer of buttercream and add sprinkles on top. Let the cookies stand at room temperature until the frosting sets before storing (it should form a crust).