Make the Cookies

1. Combine the flour, cornstarch and salt in a medium-sized bowl and set aside.
2. Add the butter and sugar to a large mixer bowl and beat on medium speed for 2-3 minutes, until well creamed. You should notice that it gets lighter in color and creamier in texture.
3. Add the egg and vanilla extract and mix until well combined.
4. Add the dry ingredients and mix just until the dough is well combined. Dough will be thick. It may seem a little crumbly at first, but it’ll come together. Don’t over mix. You can help it finish coming together by hand with a spatula, if needed.
5. Refrigerate cookie dough for at least an hour or up to 3 days. You don’t have to refrigerate the cookie dough, but the cookies turn out a little nicer and more tender if you do.
6. Preheat the oven to 350 degrees and line a cookie sheet with a silicone baking mat.
7. Bring the cookie dough back to room temperature so it’s easier to work with and divide the cookie dough into two equal parts. Roll each part out to about 1/4 an inch thickness between two pieces of parchment paper.
8. Transfer the parchment-lined cookie dough onto a cookie sheet and place it in the freezer for about 5 minutes. You don’t have to freeze the dough before cutting the cookies out, but it gives you sharper edges on your cookies and it makes it easier to cut and transfer if the dough is firm.
9. Remove cookie dough from freezer, peel off the top layer of parchment paper and immediately cut into shapes. Transfer cookies to cookie sheet.
10. Bake for 7-10 minutes or the cookies look done and just before they start to brown on the edges.
11. Allow the cookies to cool for 3-5 minutes, then remove to a cooling rack to finish cooling.
12. Continue rolling the dough, cutting out cookies and baking them until you’ve used all the cookie dough.

Make the Icing & Decorate

1. When cookies are baked and you’re ready to decorate them, make the icing. Add the powdered sugar, corn syrup, vanilla extract and 4 tablespoons cream to a medium-sized bowl. Whisk together until well combined. It may seem dry at first, but it’ll come together.
2. Add additional milk or cream to get the right consistency.
3. Divide the icing into as many bowls as you need for the colors you want. Stir in gel icing color, a little bit at a time, until it reaches your desired shade.
4. Add the icing to squeeze bottles or piping bags with small round tips for piping, or use a knife or offset spatula to spread the icing onto your cookies. Add sprinkles, if desired.
5. Allow the icing to dry. For it to be fully hard and able to be stacked on, give it 4-5 hours or overnight.