To make the caramel cream: Heat sugar and water in a saucepan over medium heat. Let boil and watch carefully, do NOT stir.
When the mixture turns an amber colour, about 10-15 minutes, turn off the heat and add the cream. Cool in pan for 10 minutes, then transfer to a bowl to cool fully.
To make the cake: Preheat oven to 180 C / Gas 4. Fully line two 20cm round cake tins.
Cream butter and sugar together until light and fluffy. Add eggs, one at a time, beating after each addition. Stir in mashed bananas.
In a small bowl, mix together bicarbonate of soda and milk. Gradually mix in self-raising flour and milk to the banana batter. Divide evenly into the two tins.
Bake in preheated oven for 30 minutes. Allow to cool before turning out. When cakes are cool, place in freezer on separate plates.
Beat the cooled caramel cream using an electric beater until fluffy. This step takes a while, so be patient. Add butter gradually, about 30g at a time, beating well after each addition. Continue until all the butter has been used up.
Remove cakes from freezer. Slice each cake in half horizontally, using a serrated knife. If the cake has a dome, shave this off to create a flat surface.
Place 1 layer of sponge cake (cut side down) onto a serving plate. Spread with caramel cream. Layer another cake on top and spread with caramel cream. Repeat until you have four layers. Spread caramel cream all over the top and sides of the cake, cover and chill.
To make the chocolate fondant: Combing icing sugar, butter, cocoa and milk together in a heatproof bowl. Put a little hot water in sink. Rest bowl in the sink and stir until combined. Drizzle over the cake before serving.
Lovely cake when finished but when adding the cream to the caramel do it slowly! Mine went into a lump but it did dissolve as I continued to stir over a low heat. Also make sure the caramel is fully cold before adding the butter as it can split. I didn't bother with the chocolate fondant on top. It is worth the effort though. - 08 Apr 2014
Lovely cake, very tasty. All the family really enjoyed it and even ended up sharing the recipe with some friends. The only tricky bit was the chocolate top as it didn't seem to drizzle very well but otherwise I couldn't fault it! - 07 Oct 2012