In a 5- to 6-quart pan, combine apple cider, cinnamon sticks, cloves, and nutmeg. Cook, covered, over medium-high heat until steaming, about 14 minutes. Reduce heat to low to keep hot. Set pan on a tabletop burner or warming tray. Or pour into a thermos or insulated pitcher. Ladle or pour into cups and add vodka to taste (if desired).
Pumpkin Spice-infused Vodka: Cut 1 vanilla bean (6 in.) in half lengthwise. With a vegetable peeler, shave 12 thin ribbons (4 to 6 in. long and about 1 in. wide) off a rinsed piece of pumpkin or banana squash. In a 1- to 1 1/2-quart jar, combine vanilla, pumpkin, 1/2 of a whole nutmeg, and 1 bottle (750 ml. or 1 qt.) vodka. Seal jar and let stand at least 4 days or up to 3 months. The flavor intensifies the longer it stands; remove flavorings once vodka tastes as strong as you like.