1. Preheat oven to 350 degrees. Combine vanilla and sweetener and mix well. Mix in ginger, walnuts, cinnamon, and cloves. Let stand.
2. Cut apples crosswise ¼ from the top, and keep the top. Core each apple and remove the stem and seeds. Squeeze a little lemon zest in each one. If needed, trim the apple bottoms so that they sit steadily. Place the apples upright in a baking dish. Spoon the filling into hollow of each apple.
3. Fill the baking dish with enough water to form a 1/2-inch pool around the apples. Bake for 1 hour and 15 minutes, or until apples are tender.
4. Transfer the apples to a serving plate. Pour the reaming liquid from the baking dish into a small saucepan. Cook over a medium-high heat until it becomes syrupy, about 15 minutes. Drizzle the date paste or syrup over the top of each apple. Top them with fresh cranberries, blueberries, or acai berries.