The Sandwich Camembert Rôti is defined by a change of state. The camembert is not sliced cold but baked until its center turns molten, then scooped warm into bread, so the cheese behaves like a hot, savory spread rather than a solid layer. Camembert is Normandy's bloomy-rind cow's-milk cheese, milky and mild young and deeper and mushroomy as it ripens; roasted whole, the rind holds while the paste inside slackens to a flowing cream. On a sturdy crusted loaf, that warm molten cheese is the whole filling, and the heat is what separates this from the cold camembert sandwich it otherwise resembles.
The craft is in handling cheese that has gone liquid. Roasting concentrates the camembert's savor and turns it pourable, which means it soaks rather than sits, so it has to be scooped into bread that can take it: a firm crust and a tight crumb that hold the line while the warm cheese seeps a little into the inside surface and stops there. A thin spread of butter, or none, is enough, since the cheese is now both the richness and the moisture. Portion is the discipline; molten camembert is intense and saturating, so a measured scoop reads as luxurious while too much turns the sandwich into soaked bread. It is at its best within a minute or two of being filled, while the cheese is still flowing and aromatic; let it stand and the camembert tightens back toward a paste and the crust loses its snap as the steam works through it.
Variations lean on what survives the heat. A clove of garlic or a sprig of thyme baked into the cheese carries through as a roasted aroma; a thread of honey or a spoon of fig against the warm paste leans it sweet; a few crushed walnuts add a crunch the soft filling otherwise lacks; a thin slice of jambon de pays under the cheese adds cured salt. Each is a recognizable turn on the same molten-cheese idea. It belongs with the regional cheese sandwiches the catalog groups under Baguette Fromage, and its specific contribution is camembert taken to the point of flow, a cheese turned into a hot spread that the bread has to be built to contain.