This can be made in a slow cooker. When using a slow cooker, we will make a larger batch. Add a gallon of apple cider to the slow cooker along with 5 cinnamon sticks, 5 whole star anise, about 1 tablespoon of cloves, a handful of orange slices, and 4 quarter-sized slices ginger. Cook for about 4 hours on LOW. This will make enough for 12 to 16 drinks. Add about 1.5 ounces of rum to each serving.
2 (3-inch) cinnamon sticks
2 whole star anise
3 whole cloves
4 1/2 cups apple cider or unfiltered apple juice
1 small orange, sliced
1 quarter-size slice fresh ginger
3/4 cup spiced rum
Heat a medium saucepan over moderately high heat. Add the spices and toast, swirling them around the pan, until fragrant, about 2 minutes. Add the apple cider, orange slices and ginger. Bring to a simmer then reduce the heat so that the cider is barely simmering. Cook for 10 minutes.
Remove the pan from the heat and stir in rum. Pick out the spices orange slices, and ginger then divide between four mugs.