Before preparing the cookie dough, take out ¼ cup of sugar and 1 tbsp of cinnamon for rolling later
Cream together butter, remaining sugar, flax eggs, plant milk, vanilla extract and remaining ground cinnamon.
Add the flour, cream of tartar, baking soda and salt in small portions until the dough begins to form. This dough will be slightly thicker than usual. If needed, add more milk.
Allow dough to rest in the refrigerator overnight or in the freezer for 1 hour. While the dough is resting, mix the reserved cinnamon and sugar and set aside.
Once rested, preheat oven to 350°F and start to roll the dough into balls using your hands. For more uniform balls, use a medium cookie scoop or spoon.
Roll balls into the cinnamon sugar and place on a parchment lined cookie sheet.
Bake cookies for 11 - 13 minutes or until desired crispyness is achieved.
Allow cookies to cool before enjoying!