From that old standby, The Joy of Cooking. It makes a dessert that has a pudding/custard bottom with a spongy top. I have not decided over the many years I have cooked this if the orange or lemon is my favorite. If I could not have chocolate on a desert island, I would want lemon. I serve it only for company, for some reason, so my friends for four decades get it tomorrow night! Watch the oven carefully; you want the top browned, but not burned.