Preheat your oven to 325° and line a rimmed, metal sheet pan with a silicone mat.*
In the bowl of your mixer, fitted with a paddle attachment, cream together the butter and sugar until light and creamy. About 2 minutes.
Add one egg at a time, mixing well after each one. Then add in the vanilla.
Whisk together the flour, cream of tartar, baking soda and salt. Gradually add the flour mixture to the batter, mixing until just incorporated.
Combine cinnamon and sugar in a bowl.
Measure 1-1/2 tablespoons of cookie dough, roll into a ball and coat in the cinnamon sugar. Place the rolled cookie balls 2-inches apart, 12 per pan and bake for 10 to 12 minutes.
Allow the cookies to cool on the pan for a few minutes before transferring to a wire rack to fully cool.
Why silicone? Well, I did bake a batch on a parchment lined metal baking sheet and they came out thinner and less "lofty". They tasted the same, but didn't have that signature snickerdoodle appearance.