Flan Imposible (Impossible Chocolate Flan) - You fill a caramel-lined cake pan with chocolate cake batter, pour a layer of flan on top, and bake. When it comes out of the oven, you find that the flan has disappeared, and all you see is chocolate cake. You wait for it to cool, unmold it, and there is the flan! This is a sticky, rich, sweet dessert that is not for the faint of heart. fine cooking.