Melt the butter in a pan with a light-colored bottom over medium-low heat. Continue heating, stirring often, until the butter browns on the bottom of the pan. Remove from heat (transfer to a heat-proof bowl if desired) and place in the fridge to cool for 20-30 minutes.

Preheat the oven to 350˚F.

Put the cooled brown butter (be sure to scrape the bowl to get all of the brown bits), brown sugar, and granulated sugar in the bowl of a stand mixer. Beat for 2-3 minutes.

Add the eggs and vanilla. Beat 1-2 minutes, until light in color and fluffy in texture.

In a separate bowl, combine the flour, cream of tartar, baking soda, and salt. Add to the mixing bowl and stir until combined.

Make the cinnamon sugar coating by mixing the granulated sugar and ground cinnamon in a small bowl.

Use a two tablespoon size dough scoop to scoop the dough into balls. Coat the cookie dough balls in cinnamon sugar and place on parchment covered baking sheets

Bake at 350˚F for 8-11 minutes.

Allow the cookies to cool slightly and then transfer to a wire rack to cool completely.