Classic St. Louis Gooey Butter Cake vs Traditional Steamed Treacle Sponge Pudding with Custard

Both desserts lean on butter, sugar, eggs, milk and vanilla, yet they land in very different places. The gooey butter cake is baked: a pressed base of flour, sugar, melted butter and egg sits beneath a rich cream cheese and powdered-sugar layer that turns golden at the edges but stays slightly gooey in the centre. The treacle sponge is steamed instead, its creamed butter-and-sugar batter becoming a soft sponge topped with golden treacle once turned out. Most of its milk and vanilla go into a warm custard thickened with egg yolks and cornflour, served alongside.