CRUST : Put everything for the crust in a food processor, mix until it sticks together. Place half of the mixture in a 28 cm pie pan and press down firmly. To line the sides, take a small amount, press it into a sausage shape, and push it against the sides, pressing firmly. Line slightly higher than the top edge. Bake for 15 min in a preheated oven at 170°C. Let cool.
FILLING : Put the cornstarch, cane sugar, and vanilla in a saucepan. Rub out the lumps. Add milk. Set over low heat, stirring constantly until you get a thick smooth pudding, pour into a bowl, cover with plastic wrap, and let cool.
Open the can of coconut milk, separate the solid part from the liquid. Place the solid coconut cream in a cold bowl and whip airy with 1 tbsp powdered sugar. Stir the pudding well until you have a smooth mixture again. Mix this into the cooled pudding.
TOPPING AND CRUST Spread the bottom with the melted chocolate. Slice the bananas, add the agave syrup, lemon juice, and lime zest. Top the crust with some of the slices. Evenly distribute the filling over it. Spread the rest of the bananas on top.
Tips
If you still have sweetened almond milk, use much less cane sugar. If your cake shape is smaller and you have some dough left, bake it: this is your perfect breakfast crumble!