In a very large bowl, stir together the flours, salt, yeast and brown sugar. Add cranberries, raisins, dates, hazelnuts and walnuts. Add cinnamon and allspice. Stir to combine.
Measure 4 1/2 cups of lukewarm water and add to flour mixture stirring with your hands to incorporate (the dough will be super sticky). Divide dough into two equal ball portions and place second dough ball into a separate bowl.
Cover bowls with plastic wrap and allow dough to stand at room temperature overnight. They will puff up slightly.
Flour a large board thoroughly then place one of the dough balls on it and knead by hand for 3-5 minutes until dough soft and smooth.
Sprinkle dough with flour and cover again with plastic wrap and allow to sit at room temperature for another 2 hours. Repeat with the second dough ball.
Place a Dutch Oven into a cold oven and then set temperature of oven to 500°F.
Taking one of the dough balls at a time, dust dough with a generous amount of flour on top and bottom then sprinkle with turbinado sugar on top.
Place dough into preheated Dutch Oven pot and cover. Bake for 30 minutes. Uncover and bake for another 10-15 minutes. Remove and allow to cool completely on wire rack. Repeat for second loaf.
Once cooled, slice and enjoy!