Preheat the oven to 160C/325F/gas mark 3
Use a 23cm/9 inch round cake tin.
Grease and line the cake tin. Sieve all the dry ingredients. Mix the condensed milk, warm water and vanilla essence together. Rub the butter into the flour until it resembles fine breadcrumbs. Pour the wet mixture into the dry and mix thoroughly. Pour into the prepared tin and bake for 40-45 minutes. Let the cake cool in the tin before turning out.
Variations.
For a plain sponge cake, substitute 50g/2 oz/1/2 cup cornflour for the 50g/2 oz/1/2 cup carob powder.
For a custard sponge cake, substitute 50g/2 oz/1/2 cup custard powder for the 50g/2 oz/1/2 cup carob powder.
For a coffee sponge cake, 50g/2 oz/1/2 cup decaff. coffee powder for the 50g/2 oz/1/2 cup carob powder.
