Whole Orange Spice Cake | Mary Berry

Ingredients

• For the Cake
• 1 small thin-skinned orange
• 275g (10 oz) self-raising flour
• 3 level teaspoons baking powder
• 275g (10 oz) caster sugar
• 225g (8 oz) butter, softened
• 4 eggs
• 1 teaspoon ground cinnamon
• 1 teaspoon mixed spice
• For the Orange Filling
• 50g (2 oz) butter, softened
• 175g (6 oz) icing sugar, sifted, plus a little extra for dusting
• 2 level tablespoons orange pulp, reserved from the cake