I recently learned that baking soda (sodium bicarbonate) was only discovered in the 19th century, which made me wonder - did cakes as we think of them exist before that?
From The World of Jewish Desserts by Gil Marks:
"The earliest cakes consisted of fried patties of mashed legumes or grain flavored with honey. After yeast breads developed, bakers added honey and other enriching ingredients to create lighter, more versatile cakes. Middle eastern baking became further refined with the popularization of sugar, first grown in the region in the fourth century CE and having largely replaced honey by the seventh century. Soon bakers began to beat eggs with sugar, creating lighter treats such as sponge cake, and utilized a host of spices and nuts.
The situation in Europe was vastly different, marked by relatively primitive cooking techniques, coarse flour, and the absence of sugar. The early Ashkenazic dessert repertoire included fluden (layered pastry), obliet (a waffle cookie), boonyish (doughnuts), various honey cakes, a cake made from the skins of fermented grapes, bird-shaped pastries, and baked apples. Medieval leavenings, such as wood ash, left a disagreeable taste, requiring the addition of copious amounts of spices and resulting in heavy cakes such as lebkuchen (gingerbread) and lekhach (honey cake).
Middle eastern baking advances, along with sugar, first reached Europe through the major ports of Italy in the twelfth century, during the Crusades. Italian chefs adapted these new baking techniques to create light, airy cakes called torta (Latin for "a round bread"). Sponge cake was transformed into genoise, named after the city of Genoa. By the thirteenth century, torten reached western and central European Jews, as first mentioned in the Tashbetz, a work by Samson Ben Zadok, a student of Meir of Rothenberg. The first record of these desserts in non-Jewish German sources, however, is dated some two centuries later, in 1418. Subsequently, Sephardic exiles brought their cakes and techniques to the areas in which they found refuge, throughout the Mediterranean, as well as Western Europe and even America.
In the seventeenth century, the popularization of sugar in Europe due to cheap sources from the Caribbean resulted in a new era of cake making. Flavors became more refined, and baking techniques more sophisticated. The English invented a cake lightened by beating butter with sugar, which evolved into the still-popular pound cake. When someone baked a pound cake batter in a thin layer and then spread it with jelly and rolled it up or stacked it, they produced the classic jelly roll and the first layer cake.
The advent of baking powder in 1856, around the same time that the cast-iron oven replaced the brick hearth, marks the beginning of modern cake making. Soon a large variety of elaborate layer cakes appeared. In the 1930's, the first cake mix, for gingerbread, was created. With the advent of World War II, mixes gained unprecedented popularity, partially because they were not included in rationing. For many households, cakes made from scratch became a memory of the past. Still, nothing compares to the taste of a homemade cake."