Preheat your oven to 350°F (175°C). This ensures that your pie bakes evenly.
In a mixing bowl, beat the softened butter, light brown sugar, and granulated sugar together using a whisk or electric mixer until the mixture is light and fluffy, about 2-3 minutes.
Add the large egg and vanilla extract to the butter-sugar mixture. Mix until fully combined and smooth.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Gently fold in the dark/semi-sweet chocolate chips, ensuring they are evenly distributed throughout the dough.
Spread half of the cookie dough mixture into the bottom of your greased pie pan. Pour the melted Nutella over the dough, spreading it evenly. Drop spoonfuls of the remaining cookie dough over the Nutella layer, creating a rustic look.
Place the pie in the preheated oven and bake for 25-30 minutes, or until the edges are golden brown and the center is set but still slightly gooey.
Allow the Nutella Cookie Pie to cool in the pan for about 10 minutes before slicing. Serve warm or at room temperature with your favorite toppings.