Streuselkuchen (German Crumb Cake) vs Zesty Lemon Drizzle Cake

Both cakes rely on butter, sugar, egg and milk, yet they put them to very different use. The Streuselkuchen uses lukewarm milk to activate yeast for a soft, kneaded, risen dough, then rubs cold butter into flour and sugar for a thick layer of coarse, golden crumbs; a little lemon zest in the dough is purely optional. The Lemon Drizzle Cake creams butter and sugar until fluffy and rises with self-raising flour and baking powder. Its sticky, sharply citrus top comes from lemon juice and sugar soaked into the hot cake.