Can I Bake The Birthday Custard Sponge In A Sheet Pan?

Our answer

NIgella's Birthday Custard Sponge (from FEAST) is a Victoria-style sponge cake that uses custard powder to give the sponge a yellow colour, a vanilla flavour and a tender crumb. The cake is baked in two 20cm (8-inch) round pans.

Unfortunately we think that the sheet pan described is much too big for the amount of cake batter in the recipe. The batter will be spread very thinly and it is easy to overbake the sponge in this scenario. You would need to drastically adjust the baking time and as we have not tried this we can't advise on any time and temperature adjustments. Also, the cake layers will be very thin, which would make them more prone to breaking up. You could try baking the sponges in 23cm (9-inch) pans for a shorter time, but as we haven't tried this ourselves, unfortunately we can't advise on how long this would be.