Cut a neat square in the middle of the baguette and brush with garlic butter.
Sprinkle with a layer of mozzarella and top with a layer of lasagna sheets, trimmed to size so they fit snugly inside the baguette.
Spoon in a layer of the ragu followed by the béchamel, parmesan and another layer of pasta. Repeat for as many times as your bread permits, finally topping with a layer of pasta, followed by béchamel and the two cheeses.
Wrap in foil and bake at 180°c/360°F for 20 minutes, followed by grilling/broilling for another 5 minutes.