This luxurious chocolate cake is a real treat! It can also easily be made vegan.
Line three 20cm (8in) round baking tins with parchment. Preheat the oven to 190°C/Gas Mark 5.
Sieve the flour into a small bowl and set aside.
Put the butter and caster sugar into a large bowl and beat together until light and fluffy.
Add two eggs to the bowl (or all of the chickpea flour and water) and beat well. Sieve the cocoa powder into the bowl and stir to combine. Add the remaining eggs, beating them in one at a time. Beat in half the flour followed by the milk and vanilla. Stir in the remaining flour.
Divide the mixture between the prepared cake tins, smooth the top, then bake for 30-35 minutes.
Put the butter into a bowl and beat until light and fluffy. Sieve the icing sugar into the bowl and beat to combine.
Divide the mixture between the top of two cold cakes and spread it out evenly. Place one cake on top of the other. Place the third sponge on top.
Put the cream into a saucepan over a medium heat. When it is almost boiling, remove from the pan from the heat and stir in the chocolate.
Allow the topping to cool, stirring until it thickens slightly.
Spread the topping over the top and sides of the cake, scatter over some marshmallows, then sieve a little cocoa over the top to finish.