- Preheat oven to 180°C. Grease and line a heart-shaped cake tin or 22cm springform tin with baking paper.
- Place the almond meal, coconut, coconut sugar, cacao, buckwheat flour, baking powder and chia seeds into a bowl and stir to combine.
- Combine the peanut butter, banana and coconut water, then fold into the dry ingredients.
Spoon the mixture into the prepared tin and bake for 40–50 minutes or until a skewer comes out mostly clean when inserted in the centre. (It will be slightly moist because of the nature of the cake.)
- Allow to cool for 10 minutes in the tin before turning out onto a wire rack to cool completely.
- To make the topping, place the banana, cacao, maple syrup and tahini into a food processor and process until smooth and creamy.
- Spread over the cooled cake, top with the flaked coconut and drizzle with the maple syrup.