1. Preheat the oven to 180C. Grease a 22cm round cake tin or kugelhopf tin and lightly dust with flour, shaking out any excess.

2. Using electric beaters, cream the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Add the vanilla, poppy seeds and orange zest and stir until well combined.

3. Sift the flours into a bowl. Using a large metal spoon, gently fold the flour into the butter mixture, alternating with the milk, until just combined and almost smooth.

4. Spoon the batter into the prepared tin and smooth over the surface. Bake for 45 minutes, or until a cake tester inserted into the centre of the cake comes out clean. Remove from the oven, leave in the tin for 10 minutes, then turn out onto a wire cake rack to cool slightly.

5. While the cake is baking, prepare the candied citrus. Cut the oranges and lemons into slices about 4mm thick. Place 250g of the sugar in a heavy-based frying pan with 80ml (⅓ cup) water. Stir over low heat until the sugar has completely dissolved. Bring to the boil, then reduce the heat and simmer. Add a quarter of the fruit slices to the syrup and simmer for 5–10 minutes, or until the fruit is transparent and the syrup is reduced and toffee-like. Lift out the fruit with tongs and cool on a wire rack.

6. Add an extra 90g (heaped ⅓ cup) sugar to the syrup and stir to dissolve. Simmer a second batch of fruit slices in the syrup as before, then remove. Add another 90g sugar to the syrup and stir to dissolve, then simmer a third batch of fruit slices in the syrup, then remove. Repeat with the remaining sugar and fruit slices. Reserve the syrup and allow the candied citrus slices to firm.

7. Place the warm cake, still on the wire rack, over a tray. Pierce all over with a cake skewer, then pour the hot syrup over, allowing it to soak in — if the syrup is too thick, thin it with a little orange juice. Set the cake on a serving plate and arrange some of the firm candied citrus slices over the top.

Tip: Orange poppy seed cake is best served within a few hours of decorating. Any left-over candied fruit can be kept between layers of baking paper in an airtight container for up to 2 days.