A genoise sponge is a classic European sponge cake that is light and fluffy in texture, made with eggs, sugar, flour, and sometimes melted butter and vanilla extract. It is named after the Italian city of Genoa and is often used as a base for European-style tortes and cream-filled cakes. Unlike other sponge cakes, genoise is a whole-egg cake, meaning that the eggs and sometimes extra yolks are beaten with sugar and heated at the same time to a stage known as the "ribbon stage". This process helps to suspend air in the batter during mixing, providing volume and resulting in a light and airy cake. Genoise sponge cakes are typically served sliced and filled with fresh fruit, jam, and whipped cream. To make a genoise sponge cake, it takes careful attention to detail as well as a light touch, as the flour must be folded into the batter gently to avoid ending up with a dense cake.