Preheat oven to 350°F. Line baking sheets with parchment paper and set aside.
In a large bowl, whisk together flour, cream of tartar, baking soda, and salt. Set aside.
Using a mixer, beat the butter and sugar together on medium speed until creamy and smooth, about 3 minutes. Add the eggs and vanilla extract and mix until combined, about 1 minute.
Slowly add the dry ingredients, with the mixer on low, about 1 minute. Stir in the white chocolate chips until combined.
Shape dough into balls, using about 2 tablespoons of dough. Mix ¼ cup sugar and the cinnamon together in a small bowl. Roll balls in cinnamon-sugar mixture.
Place 3-inches apart on prepared baking sheets. Bake 8 to 10 minutes or until set around the edges and centers are still soft. Do not overbake, it’s better to remove them from the oven when they appear slightly underdone as they will continue to cook while cooling.
Remove from the oven and let cookies set up on the baking sheet for 2 minutes. Transfer to a wire rack and cool completely.