Set a large pot over medium heat and add the cinnamon sticks, cloves, star anise, allspice berries, and crushed cardamom pods. Toast for about 2 minutes, shaking the pot once or twice, until fragrant. Watch closely so they do not scorch.
Pour in all 8 cups of fresh apple cider. Add the sliced ginger and orange rounds, tucking them into the liquid. If using a spice bag, add the toasted spices to the bag first, then drop it in. Otherwise let the loose spices float free and plan to strain later. Give everything one gentle stir.
Raise the heat to medium-high just until you see the first small bubbles break the surface. The moment it begins to bubble, lower the heat to low so it barely simmers. Do not let it reach a rolling boil.
Let the cider simmer gently, uncovered, for 25 to 30 minutes. Skim off any pale foam that gathers on top with a spoon. Around the 20-minute mark, taste and remove the star anise if the licorice note is getting strong.
Stir in 2 to 3 tablespoons of maple syrup, starting with less. Grate in ⅛ to ¼ teaspoon of fresh nutmeg. Taste again and adjust, adding more maple syrup only if needed.
Turn off the heat. Lift out the spice bag, or pour the cider through a fine mesh strainer into a clean pot or heatproof pitcher. If making a spiked version, stir in the bourbon, rum, or brandy now. Ladle into heatproof mugs, garnish with a fresh orange slice and a cinnamon stick, and serve hot.