Oil the outside of a dome-shaped mold. Beginning at the bottom, cover it with macaroons, sticking the edges of the macaroons together with sugar boiled to the crack, or with royal icing. Just before serving turn it off the mold, and place it over a form of plain or fruit Bavarian cream, which has been hardened in a smaller mold of the same shape. There should be an inch or more of space between the two, the outer one covering the other like a cage.
A croquenbouche can also be made of little cakes cut from a layer cake with a small biscuit-cutter, and iced in two colors with royal icing, or with glace oranges, or with chestnuts. The latter are difficult to make, but are very good with ice-creams.