Make your cake first. Preheat oven to 160C/320F. Add all dry ingredients to a large bowl and mix well to combine. Mix together butter and almond milk. Try to make sure they are at similar temperatures so they mix well and don’t split. Add and whisk in eggs one at a time until well combined. Add and whisk in vanilla.
Make a well in the centre of your dry ingredients and slowly pour in your wet ingredients while mixing until all combined and mixed through. You should have a light and slightly fluffy cake batter.
Line the bottom of a 20cm/8in loose bottom sponge tin with baking paper and spray with coconut oil. Pour in your cake batter and bake for 30 minutes until golden. When you lightly press the centre of the top of the cake it should spring back. Allow to cool in the pan until cool enough to handle and then turn out onto a metal rack to finish cooling completely.
Make fresh cream icing. Add all ingredients to a bowl and give a brief mix with a spoon so the protein powder isn’t sitting on top.
Using electric beaters or similar, whip your ingredients together on low until the cream is whipped and you can get soft peaks on top and the protein powder is mixed through well. Don’t over whip or your cream will start to turn to butter. If you want your icing more yellow, you can add more food colouring.
Frost the top of the cake with your banana fresh cream icing. Serve.