Fresh, vibrant and rich, this version of Madeira cake is made by carefully creaming butter and sugar, then gradually beating in eggs and folding in flour and grated orange and lemon zest to make a smooth batter. The baked cake is decorated with a citrus glacé icing and curls of candied citrus peel.
Heat the oven to 180°C/350°F/Gas 4. Put the soft butter into a mixing bowl, or the bowl of a free-standing electric mixer, and beat with a wooden spoon or a hand-held electric whisk, or the mixer whisk attachment, until creamy. Add the sugar and beat until light and fluffy. Scrape down the side of the bowl, then gradually add the eggs, beating well after each addition, and adding a tablespoon of the weighed flour with each of the last 2 additions of egg.
Sift the rest of the flour and the salt into the bowl, then add the grated zests and carefully fold in with a large metal spoon until thoroughly combined. Transfer the mixture to the prepared tin and spread evenly.
Bake in the heated oven for about 1 hour until the cake is a good golden brown and a skewer inserted into the centre comes out clean. Set the tin on a wire rack. Run a thin, round-bladed knife around the inside of the tin to loosen the cake, then leave to cool for 15 minutes before carefully removing the cake from the tin – use the ends of the lining paper to help you. Leave on the wire rack until completely cold.
Meanwhile, make the decoration. Put the sugar and water into a small pan, set over a low heat and stir until the sugar has dissolved. Bring to the boil, then remove from the heat. Using a vegetable peeler, pare off long strips of peel from the orange and lemon and add it to the syrup. Return to a low heat and simmer gently for about 5 minutes until the peel is very soft. Remove and cool, then drain. Leave the peel on a sheet of baking paper to dry.
To make the icing, sift the icing sugar into a small bowl and stir in the juices (squeezed from the orange and lemon) to make a smooth, runny icing – add a bit more juice, if necessary. Drizzle the icing over the top of the cake, letting it run down the sides.
Using a cocktail stick or skewer, carefully lift the candied peel onto the cake and arrange in curls. Transfer the cake to a plate.