Step 1: Preheat your oven to 350°F (175°C).
Step 2: Line a 9x13 inch baking pan with parchment paper.
Step 3: In a large mixing bowl, cream together the butter, brown sugar, and granulated sugar using an electric mixer until light and fluffy, about 2-3 minutes.
Step 4: Mix in the vanilla extract and salt until well combined.
Step 5: Gradually add the flour to the butter mixture, mixing on low speed until just combined.
Step 6: Press about two-thirds of the dough evenly into the prepared baking pan.
Step 7: Spread the Nutella over the layer of dough evenly.
Step 8: Crumble the remaining dough over the Nutella layer.
Step 9: Bake for 25-30 minutes, until the edges are golden brown.
Step 10: Cool in the pan for 10 minutes, then lift out using the parchment paper and cool completely on a wire rack before slicing.
