One of the most classic cookies of all time, these soft and chewy Perfect Gluten Free Snickerdoodles are such a treat at Christmastime or any time of the year.
Preheat the oven to 375° F. Line a baking sheet with parchment paper or a nonstick baking mat and set aside.
In a medium bowl, whisk together the flour, cream of tartar, baking soda, cinnamon, and salt. Set aside. Combine the topping ingredients in a small bowl and set aside.
In a large bowl, cream the butter and sugar until light and fluffy, about 2-3 minutes. Add the egg, egg yolk, and vanilla extract and beat to combine. Scrape down the sides of the bowl.
On low speed, slowly add the flour mixture and beat just until combined.
Roll cookie dough into balls about the size of a walnut (1 to 1½ inches in diameter) and then roll the balls into the sugar and cinnamon mixture. Place on prepared baking sheet about 2-3 inches apart. Bake for 10 minutes. Allow the cookies to cool on the baking sheet for 10 minutes before removing to a wire rack to cool completely.
Store in airtight container at room temperature for up to one week or freeze for one month.