Preheat oven to 350F. Grind graham crackers in a food processor or blender until fine. Melt coconut oil and combine thoroughly with ground graham crackers until well combined. Press into a tart pan. Bake for 10 minutes and let cool before filling.
Separate the fat from the remaining liquid in the cans of coconut milk. Set liquid aside for other recipes (smoothies, oatmeal, etc). Beat the coconut cream until thick and luscious like traditional whipped cream. Fold in the maple syrup, lemon juice and zest. This will make the whipped coconut cream fall slightly. No worries. Evenly fill the baked graham cracker crust and freeze for 1 to 2 hours or until filling is thoroughly set.
Sprinkle prepared fruit over the top of the tart.
Eat now. Alternatively, the dessert can be returned to the freezer or refrigerator and eaten later. If frozen overnight, the tart will be much harder and the flavor profile will be different but still delicious.