Cut up the butter to soften. Add and blend in with a whisk the following ingredients (in this order): the caster sugar, the eggs one by one, the sifted flour, the baking powder, the zest of two oranges and the juice of one orange. Butter the cake tin.
Bake in a medium oven for approximately 40 mins.
Remove the cake from the oven and turn out of the tin.
Icing: cook the confectioner’s sugar and juice of 3 oranges over a low heat for 5 mins.
Drizzle the syrup on all sides of the cake, turning it carefully. Serve cool.
The cake can be prepared the day before and chilled overnight in the refrigerator. Delicious service with custard.