The main difference between a Swiss roll and a chocolate roulade lies in their flavor profiles. While both are rolled cakes, a Swiss roll is typically a sponge cake filled with jam or cream, often featuring a light and airy texture. On the other hand, a chocolate roulade is specifically flavored with chocolate and is usually a denser, richer cake. The filling for a chocolate roulade may also include chocolate ganache or whipped cream with a chocolatey twist.