Line the bottom of your slow cooker with parchment paper for easy cleanup.
Place the brie wheel in the center of the slow cooker (you can remove the rind from the top if you prefer, but it's not necessary).
In a medium bowl, combine cranberries, brown sugar, orange juice, honey, orange zest, cinnamon, and nutmeg. Mix well.
Spoon the cranberry mixture over and around the brie.
Cover and cook on low for 1.5 hours, until the brie is soft and gooey and the cranberries have broken down into a thick compote.
Sprinkle with nuts if using and garnish with fresh thyme. Serve immediately with crackers, toasted baguette slices, or apple slices.