What is a light soft yeast cake full of holes and served toasted called?

Brioche is a French bread known for its rich, buttery texture and airy crumb, often with a golden-brown crust. It's traditionally made with a high proportion of eggs and butter, resulting in its soft, fluffy texture and the characteristic holes you mentioned. Brioche is delicious toasted and can be enjoyed plain, with butter, or as a base for many other dishes.