Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

Using a sharp serrated knife, carefully cut the top off the sourdough bread, creating a lid. Hollow out the interior, leaving about 1-inch walls and bottom intact.

Cut the removed bread pieces and the lid into bite-sized chunks for serving alongside the bread bowl.

Remove the rind from the brie cheese and cut into small cubes. Place the cubed brie inside the hollowed bread bowl.

In a small bowl, combine cranberries, honey, minced garlic, half of the thyme leaves, salt, and pepper. Mix well to coat the cranberries.

Spoon the cranberry mixture over the brie cheese, distributing evenly throughout the bread bowl.

Drizzle olive oil over the bread exterior and sprinkle with remaining thyme leaves. If using walnuts, scatter them over the cheese mixture.

Place the filled bread bowl on the prepared baking sheet and bake for 20-25 minutes, until cheese is melted and bubbly, and bread is golden brown.

Remove from oven and let cool for 5 minutes before serving to allow the cheese to set slightly.

Serve immediately with the reserved bread pieces and crackers for dipping.