Lava cake is named for the way it is prepared, which leaves the center of the cake liquid and very hot. This method of preparation ensures that when the cake is cut open, the filling pours out slowly like a magma flow, mixing the chewy cake's exterior and its sweet, melted interior.
Molten chocolate cake is usually prepared either in special tins or in large cupcake or muffin molds, subjecting the walls and roof of the cake to higher heat than the interior so that they firm and contain the molten chocolate inside.
Molten chocolate cake is almost always served hot, as the interior can begin to set if the cake is left to sit for too long. Overcooking the cake can also lead to burnt exteriors and firm innards, a poor combination which robs the dish of much of its flavor and many of its unique qualities. The cake should be carefully timed so as not to lose its melted center.
Vanilla ice cream is often served along with molten chocolate cake, as the cold sweetness complements the warmth of the cake's molten interior. The contrast between temperatures heightens the enjoyment of actually eating the cake. The dessert is a simple one, but it has a unique profile.