Sugar Cookies

1. In a large bowl, whisk together the flour, cornstarch, baking powder, baking soda, and salt. Set aside.
2. In a separate large bowl, beat together the butter and sugar until creamed, about 2–3 minutes.
3. Beat the egg, sour cream, vanilla extract, and almond extract into the butter mixture. Turn off the mixer and scrape down the bottom and sides of the bowl a few times.
4. With the mixer on low speed, beat the dry ingredients into the butter mixture. Mix until evenly combined and there are no lumps. The dough will be thick.
5. Cover the bowl and refrigerate for at least 1 hour or up to 48 hours.
6. When ready to bake, preheat the oven to 350°F (180°C). Line 2 cookie sheets with parchment paper or baking mats.
7. Scoop the dough into balls using about 1½ tablespoons of dough each. A cookie scoop is recommended. Place the dough balls about 2½ inches apart on the lined cookie sheets.
8. Bake one sheet at a time in the middle of the preheated oven for about 12–14 minutes. The tops should look set and should not feel doughy when lightly pressed with a finger.
9. Cool the cookies on the cookie sheets.

Frosting

1. In a large bowl, beat the butter until smooth. Then mix in the shortening.
2. Add 3 cups powdered sugar, along with the vanilla and salt. Beat together, starting on low speed and gradually increasing to medium speed.
3. Beat in the whipping cream 1 tablespoon at a time, alternating with a little extra powdered sugar if needed, until you get the desired sweetness and thickness.

Decorating

1. Make sure the cookies are fully cooled. Line cookie sheets with clean wax paper or parchment paper, not the same parchment sheet used for baking. Transfer the frosting to a piping bag with a large round tip, or a freezer bag with the bottom corner cut off.
2. Squeeze frosting on top of each cookie to create a large, round dollop.
3. Place each cookie upside down on the lined cookie tray so the frosting flattens slightly. Place the cookie trays in the freezer for about 20 minutes.
4. Pour the sprinkles onto a plate. Remove the cookies from the freezer and carefully peel each cookie off the parchment or wax paper. The tops should be flat. Dip each cookie into the sprinkles, pressing down slightly so they stick.
5. Alternatively, frost each cookie with a flat-edge knife and then dip it into the sprinkles.