Spray a 9-inch glass pie dish with non-stick cooking spray and set aside.
Place almonds and oats in a food processor and process until finely ground. Turn the food processor on and add 1 1/2 cups of the of dates through the feeding tube one at a time, adding water at the end. Process until mixture is well combined.
Pour the contents of the food processor into the pie dish and use your hands to spread evenly into the dish. Place the crust in the refrigerator to chill until the ice cream is made.
Place the can of coconut milk in the refrigerator until chilled thoroughly. Combine marionberries, coconut milk, the remaining 1 1/2 cups of dates, and vanilla extract in a high-speed blender and process until smooth.
Pour the mixture into the base of an ice cream maker and freeze according to the manufacturer’s instructions.Once the ice cream is finished churning, pour it in to the pie crust. Freeze the ice cream pie for at least two hours before serving.
You can use blueberries if you can’t find marionberries.