Coarse Sea salt for sprinkling on completed cookies
In a medium sized bowl, mix the flour, baking soda, cream of tarter, cinnamon, and set aside.
To brown the butter, heat a medium saucepan to medium high heat. Add the sliced butter, whisking frequently. You will notice the butter starting to become frothy on the top and brown specks will start to form along the bottom. You have to watch it closely because the turn happens quickly and you don't want it to burn. You will start to smell a nutty aroma and once it turns to a brown color, remove from heat and let it cool to room temperature.
While the butter is cooling, cut the carmel squares into 1/4's.
In a stand mixer, combine the brown butter and brown sugar, and 1/2 cup granulated sugar. (The 1/4 cup sugar will be used for rolling in the cookies). Mix until blended and smooth.
Beat in egg, yolk, vanilla and yogurt and mix until combined. Slowly add the dry ingredients until combined.
Form the dough into a ball and cover with plastic. Chill in the refrigerator for at least 30 minutes or overnight.
Once you are ready to bake preheat the oven to 350 degrees. Measure about 2 tablespoons of dough and roll into a ball. Flatten the ball and place 1-2 caramel squares inside, wrap the cookie dough over the caramel and roll back into a ball. Make sure it is completely covered so that the caramel won't stick to the pan.
Mix 1/4 cup sugar and cinnamon in a small bowl and roll each cookie in the mixture. Place on a cookies on a parchment lined cookie sheet 2 inches apart. Sprinkle lightly with sea salt. (I used course sea salt)
Bake for 8-10 minutes, or until the edges turn lightly brown. The centers will be soft. Allow to cool for 2-3 minutes, and transfer to a wire cooling rack to cool completely.