Ingredients 2-¼ cups All-purpose Flour 1-¼ teaspoon Baking Soda ¼ teaspoons Salt 1 cup Unsalted Butter 1-¼ cup Dark Brown Sugar ¼ cups Granulated Sugar 1 Egg 1 Egg Yolk 1-½ teaspoon Pure Vanilla Extract 1 Tablespoon Plain Greek Yogurt ¾ cups Semi-Sweet Chocolate Chips ½ cups Milk Chocolate Chips ½ cups Dark Chocolate Chips 1 jar Nutella, Chilled In Refrigerator, 13 Ounce Jar Coarse Sea Salt, For Sprinkling Preparation Whisk together the flour, baking soda, and salt in a bowl and set aside. Melt butter in a saucepan over medium heat. The butter will begin to foam. Make sure you whisk consistently during this process. After a couple of minutes, the butter will begin to brown on the bottom of the saucepan; continue to whisk and remove the pan from heat as soon as the butter begins to brown and give off a nutty aroma. Immediately transfer the butter to a large bowl to prevent burning. Set the butter aside to cool for a few minutes. With an electric mixer, mix the slightly cooled butter and sugars until thoroughly blended. Beat in the egg, egg yolk, vanilla and yogurt until combined. Add the dry ingredients slowly and beat on low-speed just until combined. Gently fold in all of the chocolate chips. Chill your dough for 2 hours in the refrigerator, or place in the freezer for 30 minutes if you are super eager, although I cannot promise the same results if you do this. Preheat the oven to 350 F. Once dough is chilled measure about 1 1/2 tablespoons of dough and roll into a ball. Flatten the dough ball very thinly into the palm of your hand. Place 1 teaspoon of chilled Nutella in the middle and fold the dough around it then gently roll into a ball. It doesn’t have to be perfectly rolled but make sure that the Nutella is not seeping out of the dough. Add more dough if necessary. Place dough balls on a non-stick or parchment paper-lined cookie sheet, 2 inches apart and flatten with your hand VERY gently. Really only the tops need to be flattened a bit! Bake the cookies 9-11 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. Cool the cookies on the sheets at least 2 minutes. Sprinkle with a little sea salt. 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. Best if served a tiny bit warm.