Basic all-in-one Sponge Traybake

I am not sure why anyone would make this traybake, when there are all sorts of delicious alternatives in the book. However, as I must make everything, (and really don't want to make anything twice unless I have to!), I set about making this yesterday, with a sneaky idea in mind. Today I went to a baby shower, and when I offered to bake something, I was asked to make the lemon traybake. So, having followed the recipe for the basic sponge mix, I cut  four pieces and took this photo - not a lemon in sight! I tasted a bit of the sponge, and it was fine, quite light but nothing special, probably about a 7.0.
I then proceeded to slice the rest of the cake in half, and spread it with lemon curd, to make up for the fact that there was no lemon rind in the cake. I then made the icing sugar and lemon juice topping and spread it over the top! No one would ever know, in fact I think the lemon curd was a nice addition.