Step 1

First, brown your butter: add butter to a large saucepan and place over medium heat. The butter will begin to crackle, and then eventually foam. Make sure you whisk constantly during this process. After a couple of minutes, the butter will begin to brown and turn a nice golden amber color on the bottom of the saucepan. Continue to whisk and remove from heat as soon as the butter begins to brown and give off a nutty aroma. Immediately transfer the butter to a medium bowl to prevent burning. Set aside to cool for 5-10 minutes or until cool enough to touch.

Step 2

Once brown butter is cool, add all of it to the bowl of an electric mixer, along with the dark brown sugar and granulated sugar. Mix on medium speed for about 1 minute.

Step 3

Next, add in the egg, egg yolk, vanilla, and yogurt and beat on medium speed until well combined, smooth and creamy; about 1-2 minutes.

Step 4

In a separate bowl, whisk together the flour, baking soda, cream of tartar, 1/2 teaspoon cinnamon, and salt in a bowl. Slowly the dry ingredients to the bowl of the electric mixer and beat on medium-low speed just until combined.

Step 5

Cover dough with plastic wrap and chill in the fridge for 2-3 hours or up to overnight. If you are super eager, place in freezer for 30-45 minutes, although I cannot promise the same results if you do this. Fridge is always best! If you desire a 'puffy' cookie, place them in the fridge overnight.

Step 6

Helpful tip: If you want to make it easier to bake the cookies, I suggest rolling them into balls BEFORE chilling the dough. That way you can simply place them on the prepared baking sheet and bake! Up to you. I simply roll them into balls, place on a plate or baking sheet and place in the fridge for a few hours.

Step 7

Once ready to bake, preheat the oven to 350 degrees F. Once dough is chilled measure about 2 tablespoons of dough and roll into a ball. If dough is too hard to roll into a ball, you may need to let it sit out at room temperature for 10-20 minutes while your oven preheats.

Step 8

Meanwhile, mix 1/4 cup sugar and the 2 teaspoons cinnamon in a bowl. Roll dough balls in cinnamon-sugar mixture, then place on cookie sheet, 2 inches apart.

Step 9

Bake the cookies 8-12 minutes or until the edges of the cookies begin to turn golden brown. They will look a bit underdone in the middle, but will continue to cook once out of the oven. Bake longer if you like crispier cookies.

Step 10

Cool the cookies on the sheets at least 5 minutes. Remove the cooled cookies from the baking sheets after a few minutes and transfer to a wire rack to cool completely. Repeat with remaining dough. Makes about 24 cookies.