In a large mixing bowl, beat together butter and sugar until fluffy.
Add apple sauce, almond milk and vanilla and beat until creamy.
In a medium bowl, whisk together flour, cream of tartar, baking soda and salt.
Gradually add dry ingredients to butter mixture until creamy.
Cover and chill dough several hours or overnight for easier handling.
Remove dough from refrigerator and let set out while oven is preheating.
Combine sugar and cinnamon in a small bowl.
Preheat oven to 350 degrees F.
Line baking sheets with parchment paper or silicone mat.
Shape dough into balls and then roll in sugar and cinnamon mixture.
Place on prepared baking sheet. Flatten each cookie.
Bake for 9-10 minutes for softer cookies, longer if you like them crispy.
Place onto wire rack to cool.
Store in airtight container.