Gateau is generally used for fancy, but light or rich, often with fresh decoration, such as fresh fruit or whipped cream.Whereas a cake may remain fresh for several days after baking or even improve with keeping, a gateau usually includes fresh decoration or ingredients that do not keep well, such as fresh fruit or whipped cream.In its northeastern Old French dialect from wasel it as borrowed into English in the thirteenth century, where it survived until the seventeenth century." ---An A to Z of Food and Drink, John Ayto [Oxford University Press: Oxford] 2002 (p.138) "The word 'gateau' crossed the Channel to England in the early 19th century...They are variously called fouaces, fouaches, fouees or fouyasses, according to the district...Among the many pastries which were in high favor from the 12th to the 15th centuries in Paris and other cities were: echaudes, of which two variants, the falgeols and the gobets, were especially prized by the people of Paris; and darioles, small tartlets covered with narrow strips of pastry...In medieval and Elizabethan times they were usually quite small...Cake is a Viking contribution to the English language; it was borrowed from Old Norse kaka, which is related to a range of Germanic words, including modern English cook." ---An A to Z of Food and Drink, John Ayto [Oxford University Press: Oxford] 2002 (p. English borrowed gateau from French in the mid-nineteenth century, and at first used it fairly indiscriminately for any sort of cake, pudding, or cake-like pie...
Moulded cakes (and fancy ices) reached their zenith in Victorian times.
Most were probably rather sickly, made from cheap sponge filled with 'buttercream'..coated with fondant icing. French gateau are richer than the products of British bakers. These products naturally relaxed into rounded shapes.
They involve thin layers of sponge, usually genoise, or meringue; some are based on choux pastry. The later are rarely dairy cream; instead creme patissiere (confectioner's custard--milk, sugar, egg yolks, and a little flour) or creme au buerre (a rich concoction of egg yolks creamed with sugar syrup and softened butter) are used. By the 17th century, cake hoops (fashioned from metal or wood) were placed on flat pans to effect the shape.
This is due to primarily to advances in technology (more reliable ovens, manufacture/availability of food molds) and ingredient availability (refined sugar). When removed the icing cooled quickly to form a hard, glossy [ice-like] covering.
At that time cake hoops--round molds for shaping cakes that were placed on flat baking trays--were popular. Many cakes made at this time still contained dried fruits (raisins, currants, citrons).