Tortas de Viana

Step 1: Heat the oven to 400°F and line a 30 × 40 cm baking tray with baking paper, letting it come up the sides.

Step 2: Make the cream first. Boil the 5 ½ oz granulated sugar and ¼ cup water in a small pan for 3–4 minutes, until a drop pulled between two fingers forms a short thread (about 225°F). Let it cool for 5 minutes.

Step 3: Whisk the 6 egg yolks in a bowl, then pour in the warm syrup in a thin stream, whisking all the time. Return to the pan over a low heat and stir constantly with a spatula for 6–8 minutes, until it thickens to a soft, glossy paste that leaves a trail and has reached at least 167°F. A common mistake is using high heat: the yolks scramble and turn grainy.

Step 4: Scrape the cream into a bowl, press cling film onto the surface and leave to cool.

Step 5: For the sponge, whisk the 5 eggs, 4 ½ oz caster sugar and 1 tsp finely grated lemon zest with an electric mixer on high for 8–10 minutes, until pale, tripled in volume and thick enough to hold a ribbon for 3 seconds.

Step 6: Sift the 2 ½ oz plain flour over in two goes and fold it in gently with a large spoon until no streaks remain, keeping as much air as possible.

Step 7: Spread the batter evenly on the tray and bake for 9–11 minutes, until golden and springy, and just starting to pull from the paper. Do not let the edges go crisp or it will crack.

Step 8: Sprinkle a clean sheet of baking paper with the 2 tbsp caster sugar. Turn the sponge out onto it, peel off the lining paper and roll the sponge up from a long side with the sugared paper inside. Leave to cool rolled, about 30 minutes.

Step 9: Unroll carefully, spread the egg cream evenly, leaving a 2 cm strip bare along the far edge, and roll it up again tightly. Chill for 30 minutes, then trim the ends and slice. Dust with 1 tbsp icing sugar if you like.