Preheat the oven to 350˚F. Lightly spray a 9x13 baking dish.
In a food processor, combine the crust ingredients until it resembles coarse meal. Press on the bottom of the prepared baking dish, and bake for 10 minutes.
Meanwhile mix together the strawberries, 2 tablespoons sugar, cornstarch and vanilla.
Microwave the nutella for 15 seconds, or until melted. Spread evenly over the baked crust.
Spread the strawberry mixture over the Nutella.
In a food processor, mix together the 1/3 cup sugar, flour, 3 tablespoons butter and salt until it looks like coarse meal. Sprinkle over the strawberry mixture and bake for 30-35 minutes.