Start by soaking the dates in warm water for at least 2-4 hours to soften (if you have a high-speed blender, you can skip this step).
Preheat your oven to 180 C / 350 F / gas mark 4 and lightly grease an 8-inch baking pan with some coconut oil or line with parchment paper.
To a blender, add the almond milk, dates, coconut oil, coconut sugar, vanilla and mashed banana and blend until smooth - the mixture should look like a thick caramel sauce. Transfer to a medium-sized bowl using a spatula to scrape the sides of the blender.
In another medium-sized bowl, combine the flour, baking soda, cinnamon and pinch of salt, whisking together until well-mixed.
Add in the flour mixture to the wet mixture a little at a time, using a whisk to mix until everything is well-incorporated and there are no large lumps - careful not to over mix!
Fold in your chopped walnuts using a small spatula
Transfer the mixture into your cake pan and bake for 25-30 minutes until a toothpick or knife inserted into the middle comes out clean
Allow to cool before pouring on the sauce and toppings