1Heat oven to 400°F (if using dark or nonstick pan, heat oven to 375°F). In food processor, place 1/4 cup hazelnuts and 1 tablespoon sugar; cover and process 45 seconds or until finely ground. Add flour and 1/2 teaspoon salt; cover and process 5 seconds or until mixed. Add butter; cover and process, pulsing on and off 5 to 10 times, until mixture looks like coarse crumbs. Add water, 1 tablespoon at a time, pulsing on and off, until mixture starts to hold together.
2Press dough in bottom and 1 1/2 inches up side of 10-inch springform pan. Spread hazelnut spread over dough on bottom of pan.
3In large bowl, beat eggs with wire whisk. Add pumpkin, 3/4 cup sugar, the cinnamon, salt and vanilla. Beat until well mixed. Stir in evaporated milk. Pour over hazelnut spread.
4Bake 40 to 50 minutes or until knife inserted in center comes out clean. Cool completely, about 2 hours. If necessary, use tip of knife to loosen tart from pan. Remove side of pan. Pipe or spoon whipped cream around edge of tart. Sprinkle with grated chocolate and 2 tablespoons hazelnuts.