Heat the cider: In a large pot over medium heat, bring the apple cider to a gentle simmer (5-7 minutes), stirring occasionally.
Add spices and sugar: Stir in cinnamon sticks, cloves, star anise, brown sugar, nutmeg, and orange slices. Simmer gently for 10 minutes.
Spike the cider: Remove from heat. Stir in bourbon, whiskey, or rum and vanilla extract (if using). Adjust sweetness or alcohol to taste.
Strain and serve: Strain out spices and orange slices if desired. Ladle into mugs, garnish with apple slices and cinnamon sticks, and serve warm.