This luscious tart tastes excellent chilled, which makes it an ideal make-ahead dessert (one day ahead). The crust can be made far in advance and frozen, unbaked or baked.
Blend the flour, sugar, salt, and almonds in a food processor until the nuts are finely ground. Using on/off turns, cut in the butter until a coarse meal forms. Add the egg and blend just until dough sticks together when pinched. Dump the dough onto a piece of waxed paper or plastic. Gather the dough into ball with the paper; flatten into a square 1-inch thick, wrap, and chill 1 hour.
Line the bottom of a 9.5- or 10-inch round removable bottom tart pan with parchment paper. Cut the dough into 1-inch slices. Lay the slices in the bottom of the pan and push them together, closing all fissures completely. Line the edges of the tart with slices of dough placed horizontally around the fluted edges. Press this dough into the bottom of the crust, closing all fissures, and into the fluted rim. Refrigerate for 1 hour.
Preheat oven to 375°F. Bake the crust until golden brown, about 17 minutes. You will notice that the crust is somewhat puffed up; this should be tamped down with the flat bottom of a glass.
For the filling and topping:
Read a few tips about making caramel. Stir sugar and corn syrup in a heavy small saucepan over medium-high heat until sugar dissolves. Stop stirring and boil the mixture until the syrup turns golden brown, swirling pan occasionally, about 4 minutes. Stir in 1 cup whipping cream (mixture will bubble vigorously). Stir over the heat until any caramel bits dissolve. Remove mixture from heat. Place milk chocolate and honey in medium bowl. Pour caramel over and let the mixture rest for a couple of minutes while the chocolate melts. Whisk until chocolate is melted and the mixture is smooth. Stir in chopped pecans. Transfer filling to crust. Chill until set, about 4 hours or overnight.
Place the chopped bittersweet chocolate in small bowl. Bring remaining 1/3 cup cream to boil in small saucepan over medium-high heat. Pour over dark chocolate; let the mixture rest for a couple of minutes while the chocolate melts. Whisk until smooth. Pour chocolate mixture evenly over tart. Refrigerate until firm, about 1 hour. (Can be made 1 day ahead; keep refrigerated and serve chilled) Remove the tart from the fluted ring. Use a flat metal spatula to lift the tart off of the metal tart pan bottom. Place on a serving platter, cut tart into wedges and serve.