To make a cake roulade, first prepare the sponge cake according to your recipe. Most great roulades involve whipping egg whites and sugar to form stiff peaks, then folding the meringue into the batter so it turns out light and fluffy. Transfer the cake batter to a prepared cake roulade pan or other rectangular baking sheet pan with edges (a standard 9-by-13-inch sheet cake pan works great), then bake the cake in the oven until a toothpick could come out clean. Be careful to avoid overbaking the cake, since a dry cake will be tough to remove from the pan and roll.
After you remove your cake from the oven, move a knife along the sides of the cake, between the edge of the pan, to help it easily release from its bakeware. Then, inverting the pan, carefully turn the hot cake over onto the flattened dish towel that’s dusted with sifted powdered sugar (or cocoa powder when making chocolate cakes). Remove any parchment or wax paper from the top of the cake, then fold the towel over the short edge of the cake, and begin to roll the cake in on itself.
At this point, the towel will be within the roll — and that’s okay, because you’ll unroll the cake before filling it. Once completely rolled up in the towel, transfer your cake to a wire rack where it can cool for one to two hours.