Line botton of 9" springform pan with parchment paper; lightly grease paper. In large bowl, combine hazelnuts, almonds, mixed peel, pineapple and zest.
In medium bowl, combine flour, cinnamon, cloves, coriander, nutmeg white pepper; stir into nut mixture.
In small saucepan, combine sugar, honey and butter. Place over medium heat, stirring until butter melts. Bring to a boil and cook for 5 - 10 minutes or until a candy thermometer reaches 250°F.
Quickly stir syrup into nut mixture; mix well (work quickly so mixtures doesn't stiffen to much) Use rubber spatula, immediately scrape mixture into prepared pan and spread evenly. Bake at 300 for 40 to 45 minutes or until slightly raised and edge is firm. (The centre will still be soft. Unlike other cakes this one will neither firm up as it cooks or colour at all so you need to time it carefully).
Cool in pan on wire rack for about 45 minutes or until centre is firm to the touch. Remove side of pan and invert onto rack. Remove pan base; peel off paper. Invert panforte back on to another rack; let cool completely. Wrap panforte in foil and let stand for 24 hours.
To serve, dust top heavily with icing sugar. (foil wrapped panforte can be stored in airtight container in a cool place for up to 1 week).
Note: To toast hazelnuts, spread nuts on rimmed baking sheet and bake at 350 for 8 - 10 minutes or until fragrant and lightly browned. Transfer hazelnuts to a clean tea towel; roll nuts around, inside towel, to remove as much of the hazelnut skins as possible.