Hazelnut Date Panforte

Preheat oven to 300 F. Butter a round 8-inch cake pan (or springform pan). Line the bottom with parchment paper, and generously grease the parchment paper. In a large bowl, stir together the first ten ingredients (hazelnuts through orange zest). In a heavy saucepan over medium heat, stir together the sugar, honey, orange juice and butter. Heat, stirring until the sugar dissolves, about three minutes. Increase the heat to medium-high. Boil without stirring until a candy thermometer registers 250 degrees F, about five minutes. Remove from the heat and stir into the fruit mixture. Transfer the mixture to the prepared pan, pushing it to the sides with a wooden spoon. Bake until the top feels dry, about 50 minutes. Transfer to a rack and let cool in the pan for about 10 minutes. Invert onto the rack; peel off parchment. Let cool completely. Place the chocolate in the top of a double boiler and melt until smooth. Pour half of the chocolate over the top of the cake; smooth it with an icing spatula. Refrigerate until set (about one hour). Repeat on other side of cake. Refrigerate again until set. Before serving, dust with sifted cocoa powder.