Heat the oven to 180°C.
Cut the top off cob loaf and pull the soft bread out – place aside.
Heat olive oil in a pan, fry onion and bacon and place in a bowl.
Add the block of softened cheese, cream, VEGEMITE and grated cheeses. Mix well and fill the cob loaf.
Place bread lid on and wrap in foil.
Bake at 180°C for 45 minutes.
Remove foil and cook for a further 10 minutes.
Add the bread pieces and bake for 7-10 minutes to crisp up.