Zingy Citrus Madeira Cake recipe - The Great British Bake Off

Ingredients

• 150g unsalted butter, softened
• 150g caster sugar
• 4 medium eggs, at room temperature, beaten to mix
• 200g self-raising flour
• pinch of salt
• finely grated zest of 2 medium oranges
• finely grated zest of 1 large unwaxed lemon
• 75g caster sugar
• 100ml water
• 1 medium orange
• 1 large unwaxed lemon
• 150g icing sugar
• about 1 tbsp orange juice
• about 1 tbsp lemon juice