Preheat your oven to 300 °F.
Line a large baking sheet with silicone baking mat.
Place the chopped hazelnuts out onto the prepared baking sheet and spread in an evenlayer.
Bake for about 5-7 minutes.
Remove the baking sheets of hazelnuts from oven and set aside to cool for 5 minutes.
Now adjust the temperature of oven to 350°F.
Fo rcrust: in a food processor, add ¾ cup of toasted hazelnuts, flour, sugar, andsalt and pulse until a coarse meal like mixture is formed.
Add the butter cubes and pulse until the mixture becomes crumbly.
Transfer the crumb mixture into a large bowl.
Slowly add ice water and with a wooden spoon,mix until a dough comes together.
Place the dough into a 9-inch tart pan.
With your hands, press the dough firmly intothe bottom and up the sides of the pan.
Then trim any excess dough from the edges.
Grease one side of a piece of foil to fitinside the tart.
Place the foil piece over crust, greased sidedown.
1. Fill the crust with beans.
Bake for about 18-20 minutes.
Remove the tart pan from oven.
Carefully remove the foil with beans.
Forfilling: in a small bowl, add½ cup ofheavy cream and cornstarch and mix well.
In a medium saucepan, add the cream mixture, remaining heavy cream, Nutella andsalt and whisk until well combined.
Place the saucepan over medium heatand bring to a boil, whisking continuously.
Cook for about 3 minutes, whisking continuously.
Remove the pan of cream mixture from heat and whisk in the vanilla extract.
Place the Nutella mixture over the crust evenly and refrigerate for about 3-4 hoursor until set.
Garnish with remaining hazelnuts and serve.