Preheat oven to 350∞F.

In a small saucepan over medium heat, melt the butter, whisking constantly. Bring the butter to a simmer and continue whisking until the butter goes from yellow to golden brown and smells a little nutty. Pour the browned butter into the bowl of a stand mixer fitted with the paddle attachment and let cool for five minutes.

Add the granulated and brown sugar to the browned butter and mix on low until well combined. Add the eggs, one at a time, mixing until combined. Stir in the vanilla.

In a small bowl, combine the flour, baking soda, and salt. Gradually add the dry ingredients, mixing on low, until completely combined.

Line a 9x13 baking dish with parchment paper or spray with non-stick cooking spray.

Spread half of the dough into the prepared pan.

In a small sauce pan, heat the Nutella over low heat until it's a consistency that is easy to spread. Spread the Nutella over the cookie dough.

Use your hands to flatten pieces of the dough (it will be somewhat sticky, but very easy to work with) and place over the top of the Nutella. It's okay if there are gaps in the top layer, but do try to cover it as best you can.

Bake for 30 minutes or until the dough is golden brown and cooked through.

Cool completely before cutting and serving.