This cake has been a long time in the coming. I originally conceived it as my birthday cake, but haven't managed to find a suitable opportunity, until this weekend, to make it. I love peanut butter and the idea of using it as icing really appealed to me. I spent some time trying to work out how best to incorporate it into a cake before deciding on a triple layered cake: banana, chocolate, banana. In theory all the flavours - peanut, chocolate, banana - should be complimentary and with many different textures and elements (cake, butter icing, cream, chocolate, peanut butter crumbs) I was hoping it would be a real winner. Thankfully I wasn't disappointed.
Having overcome the challenge of getting over-ripe bananas*, the banana cakes came out really well: moist and bananary. The chocolate cake provided a structural element as well as managing to be airy and full of flavour. The banana cream filling was a good option, offsetting the rich peanut bitter icing. The curls, Snickers slices and peanut crumb provided different textures meaning each mouthful was full of different flavours and textures. I was very happy with this cake.
It was even well received at work. (Someone even described it as "heaven"!) Having been intimidated until now, I'm glad I have finally taken in a cake and it wasn't a disappointment. I fear, however, I may have set the bar rather high...
Some improvements could be to use even riper bananas, include banana chips or (salted) peanut brittle somehow to add a crunchy texture. Maybe add some vanilla or sugar to the banana cream.
*Banana ripening tip: put the bananas in a bag with a ripe tomato and/or apple and leave it some place warm.
Banana, chocolate and peanut butter cake
NOTE: This cake has many components so set-aside a day if you're going to replicate!
For the banana cakes:
3 over-ripe bananas (the skins should be dappled with black spots and their aroma should be very strong and sweet)
4oz caster sugar
4oz light muscavado sugar
8oz plain flour
1.5tsp baking powder
1tsp bicarbonate of soda
0.5tsp vanilla extract
For the chocolate cake:
4oz caster sugar
3oz plain flour
3tbsp boiling water
2tbsp vegetable oil
1tsp baking powder
1tsp vanilla extract
For the banana cream:
100ml double cream
1 over-ripe banana
For the peanut butter icing:
(quantities provided for filling/frosting separately)
4oz/6oz smooth peanut butter
8oz/12oz icing sugar
For the peanut crumb:
1oz crunchy peanut butter
0.75oz icing sugar
1. For the banana cakes start by creaming the butter and sugars together until pale and fluffy.
2. Beat in the eggs one at a time using a small spoonful of flour to stop the mix splitting.
3. Mash the bananas and beat in to the egg mixture along with the vanilla. [Don't worry if the mix looks as if it is splitting).
4. Sieve the flour, bicarb and baking powder together and fold into the butter and sugar mix.
5. Split the batter between two buttered and lined 8" cake tins and bake at 180°C for about 25mins or until the cake is done (a skewer comes out clean and the sides are starting to pull away from the tin). Allow to cool.
NOTE: Be careful handling these cakes they are VERY moist and delicate.
6. For the chocolate cake, separate the egg yolks and whites. Whisk the egg yolks, sugar, oil, water and vanilla into a smooth batter.
7. Sieve in the flour, cocoa and baking powder and beat until combined.
8. Whisk the egg whites until stiff then fold into the chocolate mixture.
9. Bake at 180°C for 40mins or until the cake is done (a skewer comes out clean and the sides are starting to pull away from the tin). Allow to cool.
10. For the peanut crumb, rub the peanut butter and icing sugar together to get a crumb texture. Bake at 180°C in a tray for 7mins then shake and toss before baking for a further 8mins.
11. For the peanut butter icing, bet together the peanut butter, butter and icing sugar. Use a milk to get a good consistency.
12. For the banana cream, whip the double cream until just holding peaks. Mash the banana and fold into the cream.
13. To compile the cake, first of all carefully top the cakes so that they are all level. Take one of the banana cakes and cover it with half of the filling icing and then top with half the banana cream.
14. Put the chocolate cake on top, and repeat the layers with the remaining icing and cream before topping with the remaining banana cake. Shape as required.
15. Use a small amount of the peanut butter as a crumb layer and cover the whole cake. Chill.
16. Generously ice the cake with the remaining peanut butter icing. Press the chocolate curls on to the side of the cake.
17. Slice the Snickers thinly (~3mm) and press into the perimeter of top of the cake. Gently press the peanut crumb into the top to complete.