A flourless chocolate cake is a type of cake

Cake

Cake is a form of bread or bread-like food. In its modern forms, it is typically a sweet and enriched baked dessert. In its oldest forms, cakes were normally fried breads or cheesecakes, and normally had a disk shape...

 made from an aerated chocolate

Chocolate

Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...

 custard

Custard

Custard is a variety of culinary preparations based on a cooked mixture of milk or cream and egg yolk. Depending on how much egg or thickener is used, custard may vary in consistency from a thin pouring sauce , to a thick pastry cream used to fill éclairs. The most common custards are used as...

. It is prepared with a whole egg foam in a manner similar to a Génoise cake

Génoise Cake

A génoise cake is an Italian sponge cake named after the city of Genoa and closely associated with Italian and French cuisine that does not use any chemical leavening, instead using air suspended in the batter during mixing to give volume to the cake...

, using low heat from the melted chocolate to stabilize the protein matrix (which contains only the starch naturally present in the chocolate) and then baked in a bain-marie

Bain-marie

A bain-marie is a French term for a piece of equipment used in science, industry, and cooking to heat materials gently and gradually to fixed temperatures, or to keep materials warm over a period of time.- Description :...

. While traditionally considered a restaurant-style dessert, flourless chocolate cake is also popular for gluten-free diets.

A similar cake with little or no flour in which the egg matrix is allowed to collapse is known as "fallen" or "molten" chocolate cake

Molten chocolate cake

Molten chocolate cake, or lava cake, is a popular dessert that combines the elements of a flourless chocolate cake and a soufflé...

 and was popularized by, among others, Jean-Georges Vongerichten

Jean-Georges Vongerichten

Jean-Georges Vongerichten is a French chef. He was born in Alsace, France, in 1956 and now resides in the United States of America. Vongerichten commands restaurants in culinary capitals Las Vegas, London, Paris and Shanghai, as well as New York's Jean Georges restaurant...

's restaurants.