Add wine, cider, honey, orange zest and orange juice to a Dutch oven or similar large pot and stir to combine.
Add the cloves, cardamom, cinnamon stick, and star anise. Bring to a simmer over medium-high heat. Reduce the heat to low and let simmer gently for 30 minutes; do not let the wine boil.
Stir in the brandy. To serve, ladle into mugs and garnish with an orange slice and cinnamon sticks.
DOUBLE BATCH: This recipe scales easily. Feel free to increase the batch size by as much as your pot will hold.
TO MAKE IN THE CROCKPOT: Add the wine, cider, honey, orange zest, and orange juice to a 3-quart or larger slow cooker. Stir to combine. Add the cloves, cardamom, cinnamon, and star anise. Cook on low until warm, 30 minutes to 1 hour, depending on your slow cooker. Stir in the brandy and serve. To keep the wine warm, leave the slow cooker on the “Keep Warm” setting. If your slow cooker does not have a warm setting, alternate between “Low” and “Off.”
TO STORE: Let your mulled wine cool completely, then pour it into an airtight storage container and place it in the refrigerator for up to 3 days.
TO REHEAT: Gently rewarm mulled wine in a large pot on the stovetop over low heat, or pour leftovers into your slow cooker and reheat on LOW until warm.