This is a take on those Italian Baci candies we all get at Christmas done in tart form. To my mind it is sort of like a pecan pie that has been pushed to its utmost limits. Rich chocolate crust topped with a decadent hazelnut and caramel filling and then drizzled with still more chocolate. Wonderful for dinner parties, adult birthdays and the holiday dessert table. It is very easy to make but it does involve some sugar work so it you shy away from such things, now is the time to summon your courage and plow ahead or move on to another recipe. This recipe comes from Cindy Mushet at Sur La Table.
The crust is a cookie dough type crust. Beat 1 stick of softened butter with 1/3 cup sugar until very smooth and fluffy. Add 1 egg yolk and beat until combined. Sift together 1 cup of all purpose flour and 2 1/2 tablespoons of cocoa and add to the butter mixture just to combine. The dough should be crumbly, do not over mix. Press the dough into the bottom and sides of a 9 inch tart pan and bake at 350 degrees for 15 minute. Check for cracks or tears and patch if necessary and then return to the oven to bake for another 15 minutes. Cool completely on a rack.
For the filling, toast and skin 1 1/2 cups of hazelnuts and set aside to cool. Combine 1/2 stick of butter and 1/2 cup of heavy cream in a small saucepan and heat just until the cream is warm and the butter melted, set aside.
In another saucepan combine 1/4 cup water, 2 tablespoons of light corn syrup and 3/4 cups of sugar. Cook over medium heat until the sugar is dissolved. Increase the heat and boil until the mixture is a light honey color. Remove from the heat and add the cream mixture (it will bubble up and sputter) and stir to completely combine and form the caramel. Add the hazelnuts and return to the heat and cook for a few minutes longer, stirring constantly, until an even caramel color appears. Pour the caramel mixture into the cooled tart shell and bake at 350 degrees for 17 – 20 minutes until it is golden brown and bubbling. Cool completely on a rack and drizzle with melted chocolate.