1 1/2cupsgingersnap cookie crumbs8 ounces - see "Notes" for gluten-free version
3/4stick6 tablespoons unsalted butter, melted
1/4teaspoonsalt
Filling
1cuphazelnuts4 3/4 oz, coarsely chopped
1cupheavy cream
11ouncesfine-quality bittersweet chocolate60% or more - not unsweetened, finely chopped
1/2cupchocolate-hazelnut spreadsuch as Nutella
Instructions
Make crust and toast nuts:
Preheat oven to 350°F.
Invert bottom of 9" springform pan (so that turned-up edge is underneath for easier removal of tart) and close side of pan onto bottom.
Stir together crumbs, butter, and 1/8 teaspoon salt in a bowl, then press onto bottom of springform pan.
Bake crust in lower third of oven 7 minutes, then cool crust in springform pan on a rack.
While crust bakes, toast hazelnuts in a shallow baking pan next to tart crust stirring once, until golden, about 5-7 minutes.
Transfer to a plate and cool to room temperature.
Make filling:
Bring cream to a boil in a 1- to 2-quart saucepan, then pour over chocolate in a heatproof bowl, whisking until chocolate is melted and smooth.
Whisk in chocolate-hazelnut spread until combined, then whisk in nuts and remaining 1/8 teaspoon salt.
Pour filling onto cooled crust and put in freezer until just set, about 25 minutes (Tart should not be frozen.) Move to refrigerator after initial 25 minutes in freezer.
Remove side of pan before serving tart.
Notes
* For ease use high-quality bittersweet chocolate chips instead of blocks of chocolate - no need to cut anything. * This tart can be difficult to cut - I recommend taking it out of the refrigerator at least 20 minutes before serving and using a large chef's knife. * Tart can be made 4 days ahead and chilled in pan, covered. * To make gluten-free/wheat-free use MI-DEL Gluten-Free Ginger Snaps. Tastes just as good as the "with gluten" version.