Whisk together the Garbanzo bean flour, xanthum gum, baking soda, and salt in a bowl and set aside. Melt butter in a saucepan over medium heat. The butter will begin to foam. Whisk. After a couple of minutes, the butter will begin to brown on the bottom of the saucepan; continue to whisk and remove from heat as soon as the butter begins to brown and smells nutty. Immediately transfer the butter to a bowl to prevent burning. Set aside to cool for a few minutes.
Mix the butter and sugars until thoroughly blended. Beat in the egg, yolk, vanilla, and yogurt until combined. Add the dry ingredients slowly and beat until combined. Gently fold in all of the chocolate chips.
Chill your dough for 2 hours in the refrigerator.
Preheat the oven to 350 degrees 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 dough around it; gently roll into a ball. Add more dough if necessary. Place dough balls on cookie sheet, 2 inches apart and flatten with your hand VERY gently.
Bake the cookies 9-11 minutes or until the edges of the cookies begin to turn golden. Cool the cookies on the sheet for a min. of 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.