Cut the bananas into chunks and freeze until firm.

Combine the blueberries, water and maple syrup in a small saucepan over medium heat. Simmer, stirring frequently, until the berries release their juices and the mixture thickens, about 10 minutes. Cool completely.

Preheat the oven 350 degrees F. Line a sheet pan with parchment. In a medium bowl, stir together the oats, almond meal, coconut sugar, salt and coconut oil. Pat the mixture into a thin layer on the prepared sheet pan. Bake for 10-12 minutes until golden and fragrant. Cool before crumbling.

Place the bananas and almond milk in a food processor and puree until smooth and creamy. Layer the banana base, blueberry compote and about half the crumble in a freezer-proof container. Gently drag a knife through the layers to swirl. Freeze until firm. Serve topped with the remaining crumble.