1/3 cup (about 1 1/4 ounces) hazelnut pieces
3 tablespoons sugar
1 cup all-purpose flour (spoon flour into dry-measure cup and level off)
1/2 teaspoon baking powder
1/4 teaspoon salt
4 tablespoons (1/2 stick) unsalted butter, cold, cut into 6 pieces
1 large egg

Chocolate Cream Filling:
3/4 cup heavy whipping cream
1/4 cup sugar
6 tablespoons (3/4 stick) unsalted butter, cut into 6 pieces
6 ounces bittersweet (not unsweetened) chocolate cut into 1/4-inch pieces
2 large eggs
1 tablespoon finely grated orange zest
1 tablespoon dark rum
1/2 cup (about 2 ounces) hazelnut pieces, coarsely chopped

Finishing:
2 ounces bittersweet chocolate melted with 1 tablespoon butter
One 10-inch fluted tart pan with removable bottom