"Excellent question! Food historians offer several theories. Each depends upon period, culture and cuisine. Generally, the round cakes we know today descended from ancient bread. Ancient breads and cakes were made by hand. They were typically fashioned into round balls and baked on hearthstones or in low, shallow pans. These products naturally relaxed into rounded shapes. By the 17th century, cake hoops (fashioned from metal or wood) were placed on flat pans to effect the shape. As time progressed, baking pans in various shapes and sizes, became readily available to the general public. Moulded cakes (and fancy ices) reached their zenith in Victorian times."The best way to read these pages would presumably be on a Kindle - they're certainly formatted for easy conversion.
Food Simplistic in design but voluminous in its content, The Food Timeline is everything you'd seemingly ever need to know about any food. The cake page is a particularly expressive example, with history recipes and trivia from a range of sources. Example: Why are cakes round?