An iced bun is a bread roll

Bread roll

A bread roll is a piece of bread, usually small and round and is commonly considered a side dish. Bread rolls are often used in the same way as sandwiches are—cut transversely, with fillings placed between the two halves.-Various forms:...

 made to a sweet recipe with an icing sugar glaze covering the top (usually white or pink). In some bakeries they are decorated as Ballet Slippers or other whimsical shapes/characters.

Sometimes, they have a small amount of raspberry or strawberry jam in the centre, which oozes out when bitten into. Also known as a "Raspberry Bun" they have many variations, mostly in size or shape but not straying from ingredients, though sometimes also coated in sprinkles or coconut. Also, some varieties have lemon curd in the centre, with lemon icing on top.