Preheat your oven to 180°C (160°C fan) or 350°F. Lightly grease a 20cm loose-bottomed cake tin and line the base with parchment paper to ensure the cake releases cleanly after baking.

In a large mixing bowl, cream together the butter and caster sugar until the mixture is pale, fluffy, and well-aerated. Add the beaten eggs, a little at a time, whisking continuously to create a smooth batter.

Sift the self-raising flour into the bowl and gently fold it in with a spatula or large metal spoon, taking care not to deflate the mixture. Add the zest of one orange and the juice of half an orange, then fold again until the citrus is evenly dispersed throughout the batter.

Transfer the mixture into the prepared tin, smoothing the surface with the back of a spoon or a spatula. Bake for 20 to 25 minutes, or until the cake is risen, golden, and feels firm when lightly pressed in the center. A skewer inserted into the middle should come out clean.

While the cake is still hot from the oven, use a skewer or cocktail stick to prick small holes all over the surface, allowing the drizzle to penetrate deeply.

In a microwave-safe bowl, combine the juice of one orange with the icing sugar. Stir to dissolve, then microwave the mixture for 60 seconds until it forms a fragrant syrup. Be cautious—it will be extremely hot.

Carefully pour or spoon the hot orange syrup over the warm cake, making sure it seeps into the holes. Leave the cake in the tin to cool completely as it absorbs the citrus glaze, intensifying its moisture and flavor.