Preheat oven to 200*C
Prepare 2x20cm cake tins greased & lined with baking paper
Pour the flours, sugars, salt and baking powder into the mixing bowl and mix together with a fork
Mash the banana with a fork and add it to the bowl along with the melted coconut oil, biscoff spread, and plant based milk
Fold everything together with a spatula to combine
Roughly break the biscoff biscuits into small pieces, pour them into the bowl and fold them into mixture
Transfer equal amounts of the mixture into the cake tins, put the tins in the oven and bake for 20-30 minutes until golden, well risen and a skewer comes out clean
Whilst the cakes are baking, make the frosting
Put the biscoff biscuits in a food processor and blitz them into a fine powder
Add the dairy free butter, dairy free milk and maple syrup to the processor and blitz them until everything comes together
Add the icing sugar to the processor and blitz into a thick icing sugar
Take the cakes out of the oven, transfer them to a cooling rack and let them cool down to room temperature
Cut the rounded top off one of the cakes and Spread half the icing on top
Put the second cake on top of the first and repeat the spreading stage until all the icing has been used
Break the decorative biscoff biscuits into small pieces into almost breadcrumb sized pieces and sprinkle them over the top of the cake