Preheat oven to 350°. In a small bowl, whisk together olive oil, garlic powder, and Italian seasoning.
Slice off the top quarter of the bread. Place the wheel of brie on top of the bread and use a paring knife to trace around it. Scoop out the inner circle of bread. Brush the olive oil mixture on the inside of the bread. Carefully, cut down around the edges of the bread to create the slices that people will tear after baking.
Sprinkle with about 1/2 cup mozzarella, place the brie on top, then sprinkle with the rest of the mozzarella. Place the bread top on top of the cheese and bake until the cheese has melted and the bread is toasty, about 20 minutes.