Jelly Roll
1 cup sugar 1 1/2 cups flour 2 teaspoons Royal Baking Powder 1/8 teaspoon salt 2 eggs 4 tablespoons hot water currant or other jelly Mix and sift dry ingredients; stir in well-beaten eggs; add hot water slowly; beat until smooth; pour into large well greased pan. Batter should be spread very thin and not more than 1/4 inch thick when baked. Bake in moderate oven about 8 to 10 minutes. Turn out on sheet of brown paper; beat jelly with fork and spread on cake. With sharp knife trim off all crusty edges and roll up while still warm by lifting one side of paper. To keep roll perfectly round, wrap in slightly damp cloth until cool. Sprinkle with very fine powdered sugar.
A hot-water sponge from a Royal Baking Powder promotional book, meant to be baked flat and fast. Everything depends on getting it rolled while it is still warm and pliable.
- Roll it hotThe hinge of the recipe is the temperature at the moment of rolling. A sponge this thin sets in a few minutes; once cool it cracks along the outer curve and will not close.
- Moderate ovenRead that as around 350F for a cake this thin; some modern jelly-roll recipes go to 375F to set the surface before the sheet dries out. Eight to ten minutes is genuinely all it needs.
- Pan size"large well greased pan" points to a shallow rimmed sheet of the jelly-roll type, roughly 10 by 15 inches. Note that the recipe's quarter inch is the thickness when baked, so the batter is spread thinner than that.
- Brown paperUnbleached kraft paper was the standard turn-out surface. Parchment lined into the pan before baking does the same job better, and a clean tea towel dusted with powdered sugar is the usual modern substitute for the rolling sheet.
- No fat in the batterThere is no butter or oil here at all, only eggs, sugar, flour and hot water. That makes it flexible while warm and dry within a day, so serve it the day it is made.
- Beating the jellyBeating currant jelly with a fork breaks the set so it spreads without tearing the crumb. Warm it slightly if it still drags. Spread thin and stop half an inch short of the far edge or it squeezes out as you roll.
- EggsTwo well-beaten eggs give the batter its body, with the two teaspoons of baking powder supplying the lift. The recipe itself directs you to stir the beaten eggs into the dry ingredients and beat until smooth.
- YieldOne roll, about ten slices.
The New Royal Cook Book was published by the Royal Baking Powder Company, and like all such books its purpose was to put the brand's name into as many recipes as possible. The jelly roll itself belongs to a family of thin rolled sponges found in nineteenth-century baking on both sides of the Atlantic, alongside the English Swiss roll and the German Biskuitrolle, and it needs no special mould and no fat. Currant jelly turns up often as the filling in period books, and currants are high enough in pectin to set reliably without commercial additions.