Preheat oven to 350 degrees F.
In a large bowl, mix together flour, cream of tartar, baking soda, and salt together. Set aside.
With an electric mixer, cream together butter (barely softened) and sugar. Add flaxseed mixture, vanilla and blend well.
Add dry ingredients to wet ingredient and mix until combined. Do not over mix.
In a small bowl, combine remaining 1/3 cup sugar and 2 tablespoons cinnamon.
Use a small cookie scoop to scoop out dough, roll into a ball and then roll in the cinnamon sugar mixture. Do this twice so they are well coated.
Place on an ungreased cookie sheet, I like to use parchment paper. Place cookies 2 inches apart.
Bake for 8-10 minutes. Let sit on the cookies sheet for a few minutes before removing to a wire rack to cool. Enjoy!