Preheat your oven to 200°C (about 390°F). While it heats, place the day-old baguette on a baking tray. Using a sharp serrated knife, make diagonal cuts about 2 inches apart along the length of the baguette, cutting about three-quarters of the way through but not completely separating the pieces. This creates pockets for the filling while keeping the bread structurally intact. I prefer day-old baguettes because they have a firmer crumb that won't get soggy from the cranberry sauce.

Starting with the cranberry sauce, use a small spoon to distribute about 1 teaspoon of the whole berry cranberry sauce into each cut in the baguette from Step 1, pressing it gently into the pockets. The whole berry variety gives you nice texture bursts throughout. Next, slice the room temperature Brie into thin pieces and tuck one slice into each cut on top of the cranberry sauce. Since the Brie is at room temperature, it will conform nicely to the bread's shape and spread easily as it melts. I like to make sure each cut gets equal coverage so every bite has both the tart cranberry and creamy cheese.

Place the filled baguette in the preheated oven for 10-15 minutes, until the Brie is fully melted and the bread exterior turns golden brown. The cheese should be visibly soft and gooey, and the garlic flavors from the baguette will intensify with heat. Keep an eye on it toward the end to prevent over-browning, as the exposed bread edges can char quickly at this temperature.