Piskótatekercs

Ingredients

• 6Eggseparated or whole, depending on the method
• 3⅛ ozSugarfor the foamy egg mixture
• 3½ ozWheat floursifted and folded in
• ¼ ozvanilla sugar1 sachet, for flavour
• 1 tspBaking powdermixed with the flour
• 1 tspBaking sodaalternative to baking powder, into the yolk mixture (optional)
• 1 pinchSaltinto the yolk mixture (optional)
• 10½ ozJamas filling, usually apricot
• 1lemongrated zest only (optional)
• 1orangegrated zest only (optional)
• 1 tbspWaterto loosen the yolk mixture (optional)
• Icing sugarfor dusting the paper and the finished roll (optional)

Method

1. Heat the oven to 170–355 °F and line a large baking sheet with parchment. Have a clean tea towel ready, or a second sheet of parchment dusted with powdered sugar.
2. Separate the eggs. Beat the yolks with the sugar, vanilla sugar and the baking powder – or baking soda, if you prefer – and, if you like, a pinch of salt, until pale and foamy; you can also add a tablespoon of water along with grated lemon and orange zest. Alternatively, whisk whole eggs plus one extra yolk with the sugar until foamy – in that case skip step 3 and the whipped whites.
3. Whip the egg whites to stiff peaks and fold them carefully into the yolk mixture so the air stays in the batter.
4. Sift the flour over the batter in batches and fold it in gently, until no pockets of flour remain.
5. Spread the batter thinly and evenly over the baking sheet and bake for 10–12 minutes, until golden. Test with a skewer – the sponge should be dry but still springy.
6. Turn the sponge out immediately onto the towel or the sugared parchment, peel off the baking parchment and roll it up loosely while still warm. Let it cool to lukewarm in its rolled shape so it holds the curve.
7. Unroll the lukewarm sponge, spread the jam evenly over the surface and leave a narrow border free along the long side.
8. Roll the sponge up firmly and let it rest in the fridge for 1–3 hours, or better still overnight.
9. Dust the roll with powdered sugar just before serving and cut it into slices.

Tips and variations

You have a choice with the batter: separate the eggs and fold in the whipped whites, or beat whole eggs plus one extra yolk together until foamy – the second way is faster, the first a touch airier. Baking soda works just as well as baking powder, and grated lemon and orange zest brings a fresh note to the sponge. If jam isn't your thing, fill the roll with chestnut cream instead. Serve it well chilled, generously dusted with powdered sugar and cut into finger-thick slices.