Preheat oven to 200° Celsius. To bake sponge base, place all cake ingredients in a bowl and mix together until well combined. Line a square cake pan with baking paper. Bake until a skewer inserted into centre of pan comes out clean. Allow to cool before cutting into squares. To coat, place all sapote coating ingredients in a saucepan at medium heat until butter melts and sugar dissolves. Blitz ingredients in the pan with a stick blender to combine. Heat until mix begins to boil gently, then remove from stovetop. Dip the cold cake squares into the ‘chocolate sauce’, before rolling in coconut to coat. Best stored in refrigerator.