Mix the courgette, bananas, margarine and vanilla bean paste in a large mixing bowl. Add the sugar and remaining dry ingredients and stir well.
Pour into the loaf tin and bake for 35 to 40 minutes until completely set.
It is cooked when a skewer inserted in the centre comes out clean. When ready, leave to cool on a rack.
Drain the cashews and dry them off in a tea towel. Mix the cashews and vanilla bean paste in a blender until you have a smooth mix.
Add the maple syrup and almond milk and blend again. Add lemon juice to taste.
Blanch the courgette ribbons in boiling water for three minutes and dry in a tea towel.
Spread the cashew nut icing over the cooled cake and decorate with the courgette ribbons.