sponge pudding is made with a mixture like that for a sponge cake. A simple sort of sponge pudding, made from equal weights of flour, butter, sugar, and eggs, and steamed in a basin, is known as canary pudding, perhaps because at some time it was served with a sauce made with sweet Canary wine.
A similar mixture may be baked in small tins shaped like a bucket, so that, when turned out, they look like little sandcastles; these are called castle puddings. They usually have a jam sauce or a sweet wine sauce poured over them.