Preparation Position rack in center of oven; preheat to 300°F. Butter 9-inch-diameter springform pan. Line bottom and sides with parchment paper; butter paper. Mix first 16 ingredients in large bowl, tossing to separate fruit pieces. Bring honey, sugar, and butter to boil in small saucepan, stirring frequently. Reduce heat to medium-low. Place candy thermometer in mixture, tilting to submerge bulb, and cook until thermometer registers 242°F to 248°F, stirring occasionally, about 9 minutes. Pour syrup over nut mixture; stir to blend. Immediately transfer mixture to prepared pan; smooth top. Bake until bubbling slightly at edges and top appears dry, about 55 minutes. Cool completely in pan on rack. Cover; let stand overnight at room temperature. Release pan sides. Remove paper from sides and bottom of panforte. Place panforte on cardboard round. (Can be made 3 weeks ahead. Store airtight at room temperature.)
Preparation Position rack in center of oven; preheat to 300°F. Butter 9-inch-diameter springform pan. Line bottom and sides with parchment paper; butter paper. Mix first 16 ingredients in large bowl, tossing to separate fruit pieces. Bring honey, sugar, and butter to boil in small saucepan, stirring frequently. Reduce heat to medium-low. Place candy thermometer in mixture, tilting to submerge bulb, and cook until thermometer registers 242°F to 248°F, stirring occasionally, about 9 minutes. Pour syrup over nut mixture; stir to blend. Immediately transfer mixture to prepared pan; smooth top. Bake until bubbling slightly at edges and top appears dry, about 55 minutes. Cool completely in pan on rack. Cover; let stand overnight at room temperature. Release pan sides. Remove paper from sides and bottom of panforte. Place panforte on cardboard round. (Can be made 3 weeks ahead. Store airtight at room temperature.)