I developed a recipe for a tart very similar to this one when I was a food editor at Martha Stewart Living. It appeared in the February 2002 issue as part of a story on chocolate desserts. I remembered it one day when my friend Jodi admitted what a chocolate lover she is...I wanted to make if for her for her birthday but we ended up going out to a restaurant to celebrate so I made it for our New Year's Eve party instead. It would be a fantatic Valentine's Day dessert too. I could not find the recipe online so I made it up as I went along...this new version is a little different than the original but it was a huge hit.
I used hazelnuts in the tart because I love their flavor. That said, removing the papery skins adds a step that can be a little tedious. You can sometimes find them with the papery part mostly removed so that is what I try to buy. You can also just replace the hazelnuts with whatever your personal favorite nut is...I have made it with pecans and I think peanuts would also be delicious.
CHOCOLATE CARAMEL TART
8 ounces hazelnuts (about 2 cups)
1 1/4 boxes famous chocolate wafers
12 tablespoons unsalted butter
1 cup sugar
1/4 teaspoon fine salt, plus additional 1/4 teaspoon coarse sea salt
1/4 cup water
2 cups heavy cream
1 teaspoon pure vanilla extract
12 ounces dark chocolate, finely chopped
Spread hazelnuts on a cutting board and press with the side of a chef's knife to break into pieces. Transfer to a baking sheet and toast in a 350° oven until fragrant, 8-10 minutes. Set aside.
Place chocolate wafers in the bowl of a food processor and grind into a coarse powder. Melt 10 tablespoons butter in a small saucepan over medium heat. Combine cookie crumbs and melted butter in a bowl and use a fork to combine until the mixture is moist and crumbly. Pour half of the crumb mixture into into an 8 1/2 inch springform pan and press into an even layer on the bottom of the pan. Add remaining crumb mixture and press into the corners and up sides of the pan. Place crust in refrigerator while preparing the caramel.
Place sugar, fine salt, and 1/4 cup water in a small saucepan over medium high heat. Bring to a boil, brushing sides of pan with a pastry brush dipped in water, without stirring. Once the sugar has dissolved and begins to brown swirl pan gently until caramel is a deep amber color. Add 1/2 cup cream, remaining 2 tablespoons butter, and vanilla and stir to combine. Pour caramel into prepared crust and top with 1 1/2 cups toasted hazelnuts. Sprinkle with sea salt and return to refrigerator while preparing the ganache.
Place dark chocolate in a metal bowl. Bring remaining 1 1/2 cups of cream to a boil and pour over chocolate. Allow to sit for 5 minutes, until chocolate is melted. Whisk mixture together and pour over caramel and hazelnuts in the tart shell. Return to refrigerator to chill for at least 2 hours or overnight. Before serving unmold the tart and sprinkle remaining 1/2 cup hazelnuts around the perimeter. Running a sharp knife under hot water for a few minutes to warm it up will make slicing easier (dry it off before using it).