Snickerdoodles

Directions

1. 1
   Line two baking sheets with silicone baking mats or parchment paper. Set aside.
2. 2
   Place butter, granulated sugar, and brown sugar in a medium bowl. Use hand mixer to beat on medium speed until well-combined, about 1 minute.
3. 3
   Add egg, egg yolk, and vanilla extract. Continue to beat until smooth, about 30 seconds.
4. 4
   Add flour, cornstarch, baking soda, cream of tartar, and salt to the bowl. Beat on low speed, scraping sides of bowl with a rubber spatula as needed, until a smooth dough forms.
5. 5
   Divide cookie dough into 30 balls, using roughly 1 1/2 tablespoons of dough for each, and arrange them 1 1/2 inches apart on baking sheets. Transfer sheets to freezer for 10-15 minutes.
6. 6
   Preheat oven to 350°F.
7. 7
   Place sugar, cinnamon, and salt in a mixing bowl. Whisk to combine. Remove baking sheets from freezer. Roll each cookie in cinnamon sugar, creating a thick coating, and return to baking sheet.
8. 8
   Transfer baking sheets to middle rack of oven.
9. 9
   Bake cookies until puffy and golden brown at edges, 15-17 minutes.
10. 10
    Check to see that cookies are done. Remove from oven or add time as needed.
11. 11
    Allow cookies to rest on sheets for 5-10 minutes, then transfer to a wire rack to cool completely before serving.