Can I Make A Vanilla Version Of The Chocolate Sheet Cake?

Our answer

Nigella's Chocolate Sheet Cake is a moist and fudgy chocolate traybake. The chocolate frosting is poured over the sponge as soon as it comes out of the oven. The warm cake absorbs some of the icing, giving the cake its fudgy texture. We are not sure that this will work quite as well if the cake and frosting are vanilla rather than chocolate so we would not particularly recommend it. Though if you really wanted to try then you could replace the cocoa with cornflour (cornstarch) in the sponge and increase the vanilla to 2 teaspoons. In the icing omit the cocoa and increase the vanilla extract to 1 tablespoon and make sure that you use a good quality vanilla extract.

Most vanilla sheet cakes are topped with buttercream rather than a glaze. So we would suggest maybe making Nigella's Birthday Custard Sponge instead. For a sheet cake size you would need to use 1.5x the ingredients quantity for the sponge. The baking time is likely to be 30-40 minutes at 180°C/160°C fan/350°F, or until the sponge is risen, firm to the touch and a cake tester inserted into the centre comes out clean. For the top only use the buttercream and again you would need to make a 1.5x quantity.