Preheat oven to 375 degrees and line a tray or baking dish with foil large enough to wrap the focaccia. Spray lightly with cooking spray and set aside.

Open the focaccia so the top and bottom are separated. Divide the mozzarella cheese in half and spread onto both halves of the bread. Spread the tapenade into a single layer onto both halves. Place the Brie slices onto the top half, then layer the prosciutto on one side and the salami on the other.

Stack the focaccia slices together to make a large sandwich, then place it onto the foil and wrap completely. Bake for 25-28 minutes, or until cheese is melted and the bottom of the bread is slightly crisp.

Allow the sandwich to cool slightly before cutting into 6 squares and serving warm.