In a medium saucepan, add 1 cup butter and melt over medium heat. Continue to whisk the butter once melted. It will start to foam at the top and you will see the color of the butter change to brown. This process only takes about 5 minutes and the turn happens quickly. Remove the pan from the heat and allow to cool for a few minutes.
In a mixing bowl, whisk together flour, baking soda, cream of tarter, cinnamon, and salt. Set aside.
Using a mixer, beat together brown sugar, sugar and slowly add the brown butter until mixed together. Add egg, egg yolk, vanilla, and greek yogurt. Mix on low until all is incorporated. Slowly add in flour mixture and mix on low until combined.
Wrap the dough up in plastic wrap and chill for at least one hour up to three. Once ready to bake, preheat oven to 350 degrees. Line a cookie sheet with parchment paper or lightly spray with cooking spray. Set aside.
Scoop the dough out about 2 Tablespoons in size. Roll into a ball. Combine the 1/4 cup sugar and 2 teaspoons cinnamon in small mixing bowl. Roll the dough balls in the rolling mixture. Place 2 inches apart on the cookie sheet.
Bake for 8-11 minutes or until the edges are lightly brown. Transfer to a wire rack to cool. Enjoy!