Can I Add Food Colour To The Birthday Custard Sponge?

Our answer

Nigella's Birthday Custard Sponge (from FEAST) is a Victoria sponge that has custard powder added to the batter. The custard powder gives a vanilla flavour and a lightly golden yellow colour.

If you are only adding yellow gel to the sponge, to intensify the colour, then it would be fine. If you are wanting to make a sponge with different colours then it is probably better to use a different recipe as the colour will be muted due to the yellow colour. Nigella's Victoria Sponge also has a fairly deep yellow colour due to the eggs and butter so it may be worth considering the Vanilla Layer Cake With Ermine Icing as this has a slightly paler yellow sponge cake due to the vegetable shortening and milk in the batter. It is worth noting also that the colours of a cake batter become more muted when the sponges are baked and as we have not tried the Vanilla Layer Cake with gel colours, we are unable to guarantee the results.