Place the pie plate you will use for baking on top of a piece of parchment paper and use a pencil to trace the outline of the bottom for the plate. (This will be your guide to spread your Nutella later). Set the parchment paper aside.
In a stand mixer fitted with the paddle attachment, cream the butter and sugars together at medium speed for 2 minutes. Add the egg and vanilla and mix an additional minute.
In a separate bowl, whisk together the flour, salt and baking soda. Add to wet ingredients and mix to combine. Stir in chocolate chips and set aside.
Roll out the pastry dough and line your pie plate. Trim and flute edges as desired. Cover with plastic wrap and refrigerate.
Take the parchment paper on which you traced an outline and place it, traced-side-down on the counter. You will be able to see the outline through the paper, but the pencil markings will be touching the counter, not the topping.
Scoop the hazelnut spread into the center of the parchment circle and spread out evenly to fill the entire shape. Freeze 10 minutes, remove from freezer, spread Dulce de Leche over the top, and return to the freezer for another 15-20 minutes OR until you can easily peel the disc from the parchment paper.
Preheat oven to 350 degrees F.
Remove frozen hazelnut and Dulce de Leche disc from the freezer and carefully peel it off the parchment paper. Lay the disc in the pie crust. Add the cookie dough and press into a uniform layer.
Bake 25-35 minutes or until the top is golden brown and the center is almost set.
Remove from the oven and sprinkle with sea salt flakes. Allow to cool for about 30 minutes (or I think its even way better the next day!) and slice and serve with ice cream and toppings. If serving the next day, cover securely with plastic wrap once cooled. No need to refrigerate.