-
Make the cookies: In a medium bowl, whisk together flour, cream of tartar, baking soda, and salt. Set aside.
-
In a mixer bowl fitted with the paddle attachment, beat butter and sugars on medium speed until light and fluffy, about 3 minutes. Add eggs, one at a time, beating well after each addition. Beat in vanilla extract. Add flour mixture and beat on low speed just until combined. Do not overmix.
-
If the dough is soft at this point, chill in the fridge for at least 1 hour, or overnight. This step also results in thicker cookies that will spread less while baking, but it's not mandatory.
-
Preheat oven to 350F/180C. Line 2 pans with parchment paper. Set aside.
-
Make the coating mixture: In a small bowl, toss together all the ingredients.
-
Shape the dough into balls, the size of 1.5 tablespoons each. Roll them in the coating mixture, and place on the cookie sheets. Bake for 10-11 minutes until cookies just begin to brown at the edges but the center is still soft. Allow cookies to cool on baking sheet for 5-10 minutes, then gently transfer to a wire rack to cool completely.
-
Store cookies at room temperature in an airtight container for up to 3-4 days. Cookies can also be frozen for up to 2 months.