Swiss Roll is a rolled sponge cake with a filling, usually jam. You slice it sideways across the end; each slice reveals a spiral pattern.
Swiss Roll tends to be the term used for this in the UK and in Canada; in America, the term used is “Jelly Roll” (though in Canada both terms are understood), because Americans refer somewhat confusingly to jam as jelly.
The sponge cake is usually a white one, but variations can be chocolate or other flavours. It is cooked thin in a flat, shallow, long baking sheet. Some advise to grease the pan, line it with waxed paper, then grease the waxed paper as well, to avoid any sticking.
The batter should have no air bubbles in it, or the cake could end up with pockets of air in it that could break the cake when it is rolled up. Don’t bake the cake too long: you don’t want the surface to get overly browned or crunchy, which would make it harder to roll.
As soon as the cake is done cooking, invert it out of the baking sheet (yes, while the cake is still hot) onto a clean tea-towel dusted with a layer of icing sugar, then slowly peel away the waxed paper from the bottom. Then, you slowly roll up the cake and the tea towel, pressing gently as you go. When it is all rolled, with the towel rolled up inside the cake, turn it so that the seam of the covering towel is on the bottom (so that it will stay in place.)
Let the cake cool this way for an hour or a bit more, then unroll it and remove the towel. Then top with the filling you are using. The filling can be jam, lemon curd, chocolate, butter cream, etc. Finally, you roll the cake roll back up again (this time without the towel) so that the topping rolls inside the roll.
The outside of the cake can be left plain, iced or dusted with icing sugar.
The cake is cut into slices for serving revealing a spiral pattern.
When the sponge is a chocolate one with a white cream filling, the cake may be referred to as Chocolate Cream Roll or a “chocolate log.” The white cream filling used in this is usually whipped cream (usually artificial whipped cream so it will have shelf life), or butter cream.
The origin is not Switzerland. Some hazard a guess of central Europe, possibly being Austrian-inspired.
In the 1960s, the Lyons company introduced mid-sized Swiss Rolls that they called “Jolyrolls.”