Place 1/2 cup of butter that has been browned into the bowl of a stand mixer. Cover in plastic wrap and place in the refrigerator for 20-30 minutes until it has chilled (does not need to re-solidify). Meanwhile, preheat oven to 350 degrees and line a baking sheet with parchment paper. (Pull your eggs out now so that they can come to room temperature)
In a large bowl, combine the (dry ingredients) flour, baking soda, ground cinnamon, cream of tartar, and salt. Whisk until combined and set aside. In a small, shallow bowl (or plate) combine 1/2 cup of granulated sugar and 1-2 tsp of ground cinnamon. Stir and set aside.
Once the browned butter has cooled, remove from refrigerator. Add the 1/2 cup of softened butter. Mix, starting on low (you don’t want to splash your brown butter everywhere). Gradually increase speed to medium-high. Beat the butter for 3-4 minutes until pale and fluffy.
Add the brown sugar and granulated sugar. Mix for 2 minutes until well incorporated.
Add the eggs, one at a time, mixing in between. Add the vanilla and mix. Scrape down the sides of the bowl and beat for another minute.
Add half of the dry ingredients to the wet, mix on low until combined. Add the remaining dry ingredients, mixing on low, and then increasing speed to medium for about one minute.
Scoop 1 tbsp of the dough and roll into a ball. Roll the dough into the cinnamon-sugar and place onto the prepared baking sheet. Place the dough 3-4” apart.
Bake for 8-10 minutes until the cookies are crisp around the edges and the centers are still slightly soft. (You may want to lightly sprinkle on a little more cinnamon-sugar onto the tops of the cookies while they are hot) Let them sit on the hot baking sheet for at least 5 minutes to set before removing them to a cooling rack. Enjoy!