Pre-soak the raisins so they are soft. To pre-soak, put your raisins in a small bowl and cover with boiling water. Let it steep for 10 to 15 minutes, and then strain the fruit and discard the water. Peel and grate the apple on a mandolin. Chop the hazelnuts. Combine all ingredients in a large bowl and cover. Soak the mixture overnight in the refrigerator. Garnish with fresh berries.
