My husband loves Nigella's Buttermilk Birthday Cake and I was wondering if I can use the same mix to make cupcakes? If so, does this affect oven temperature and what cooking time do you advise?
It is usually possible to make cupcakes from a standard sponge cake batter. We haven't tested this recipe as cupcakes so can only give suggestions rather than an exact recipe. As a rule of thumb the batter for a 2-layer 23cm/9-inch cake will make 24-30 cupcakes. However Nigella's Buttermilk Birthday Cake (from Domestic Goddess) makes a one layer 23cm/9 inch square cake. As it is one layer and a square tin we would suspect that the recipe will make around 18-22 cupcakes (it will make more if you are using the smaller UK fairy cake tins). We suggest that you fill the paper cupcake cases 1/2 full of batter.
You don't need to change the oven temperature from 180c/350F as this is a standard temperature for cupcakes and larger cakes, but the baking time will be reduced. Most cupcakes take 15-20 minutes to bake at this temperature so we would start checking them after 15 minutes. The cupcakes are done when they are firm to the touch and a cake tester comes out clean if inserted into the centre of a cupcake. If you are baking the cupcakes on different shelves in the oven then swap the pans over after 12 minutes. We would suggest that you do try to bake all of the cupcakes at the same time as the recipe contains bicarbonate of soda (baking soda) which, once activated, works quite quickly and if the batter is left standing for too long the bicarbonate of soda will expire.