Preheat the oven to 350 and prepare a cookie sheet with parchment and set to the side.
In a medium-sized bowl, combine the flour, cream of tartar, baking soda, and salt. Set to the side.
In a medium-sized bowl with a hand mixer in the bowl of a stand mixer with a paddle mixture, cream the butter with the sugar until light and fluffy, about 2-3 minutes. Add in the egg plus the egg yolk, one at a time, followed by the vanilla. Scrape down the sides of the bowl as needed.
Gradually add the dry ingredients to the butter mixture and mix until just combined, scraping down the sides of the bowl as needed.
Mix together the cinnamon and remaining sugar for the cookies to roll in. Set to the side.
Form the cookies using a cookie scoop and roll the balls in the cinnamon and sugar mixture.
Place the rolled cookie dough balls on the prepared cookie sheet and bake the cookies for 10-12 minutes, tapping the pan in the oven against the rack so the cookies will flatten, about halfway through.
Let the cookies cool on the cookie sheet for a few minutes before transferring to a cooling rack.
