Cream together butter and sugar, add eggs. Combine dry ingredients and add into mixture. Then add cranberries, 6 oz chocolate, and hazelnuts. Form into four logs the length of a full sheet tray. Divide onto two trays. Chill, preferably overnight.
Bake at 325 until golden brown. Let cool and wrap in plastic and freeze.
When ready to bake pieces, remove from freezer and let come to room temperature. Egg wash and generously coat with turbinado sugar. Slice at a diagonal into pieces the width of two fingers. Spread out on sheet tray and bake at 325 for approximately five minutes. They should still be soft on the sides when squeezed.
Melt remaining 6 oz chocolate over a double boiler or in microwave. Coat the bottom of each biscotti with chocolate. Refrigerate to harden.