¾ cups packed brown sugar (5 ¼ ounces) – dark works best
1 teaspoon table salt
2 teaspoons vanilla extract
1 large egg, at room temperature
1 large egg yolk, at room temperature
3/4 cup semisweet chocolate chips, plus extra for topping the cookies
Line a plate with parchment paper. Scoop nutella in heaping teaspoon mounds on the parchment paper - you need about 16. Place mounds in the refrigerator to harden.
Whisk flour and baking soda in a medium bowl.
In a 10-inch skillet (don’t use a nonstick skillet if possible, because it makes it hard to tell with the butter is browned), melt 10 tablespoons of the unsalted butter over medium-high heat. Once melted, swirl the pan constantly until the butter is golden brown. This entire process will take about 3 – 5 minutes, and the butter will have a nutty smell. Watch the pan closely to avoid burning the butter.
Transfer the browned butter to a large heatproof bowl, and add the remaining 4 tablespoons butter. Stir until it is melted.
Add the sugars, salt and vanilla to the butter and whisk together. Add the egg and the egg yolk and whisk until smooth, about 30 seconds. Let the mixture rest for 3 minutes. Whisk again for 30 seconds, and then let it rest 3 more minutes. Do this one more time, until the mixture is thick, smooth, and shiny.
Stir in the flour mixture, then stir in the chocolate chips.
Chill dough overnight. If you need to bake the cookies immediately, you can. I just think the cookies taste better when the dough sits overnight.
When ready to bake, preheat oven to 375 degrees F. Line 2 large baking sheets with parchment paper or a silicone mat.
Scoop about 3 tablespoon of dough. Make a deep well in the center and place a teaspoon of the refrigerated nutella in the center of the dough. Shape the dough around the nutella, covering completely. Pace onto cookie sheets, spacing the dough 2 inches apart. Bake 10 – 14 minutes, until the cookies are golden brown on the edges but still soft in the center. Gently press a few chocolate chips on the top of the warm cookies. Allow cookies to cool on the sheet for 3 minutes, then remove to a wire rack to cool completely.