Preheat oven to 190C. In a bowl, mix mulberries with white sugar and grated ginger. Be careful not to bruise the mulberries too much. In another bowl, combine dry ingredients, mixing well. Add butter cubes and work into the mix with your fingers until a crumbly texture is achieved. Place a single tightly packed layer of mulberry mixture in each of seven gratin dishes, then sprinkle crumble mixture so it is a -cm thick and covering the mulberries. Bake for 15-20 minutes until crumble is golden. Allow to cool to warm or room temperature before serving alone or with vanilla gelato.