Preheat your oven to 375 degrees and line two baking sheets with either parchment paper or silicone baking mats. Set aside. Set aside.
In a small bowl, make the cinnamon/sugar coating by combining the 1/4 cup sugar and teaspoon of cinnamon and mixing well.
In a large bowl, add the softened butter and cream for about 1 minute on medium speed, using either a hand mixer or your stand mixer, until it is smooth.
Add the sugar and mix until fluffy.
Add in the egg and vanilla and mix until fully incorporated.
In a separate medium bowl, add the flour, cream of tartar, baking soda, cinnamon, and salt. Whisk it together.
Turn the mixer on low and slowly add the flour mixture to the butter mixture. The dough will be thick.
Use a cookie scoop to portion out dough balls and roll in the cinnamon/sugar coating mixture. Line 12 per cookie sheet and bake for 10 minutes.
The cookies will be puffy - I pressed down on them as they came out of the oven with the back of a wooden spoon to help flatten them out a bit.
Let them cool on the baking sheet for about 10 minutes before transferring to a wire rack to cool completely.