Pour 1 gallon of apple cider into slow cooker. Set the slow cooker to high. Measure Mulled Cider Spice into muslin pouch - tie pouch closed. Add the pouch of Mulled Cider Spice to apple cider. Leave for 4-6 hours. Stir occasionally. Wet the rim of the glass then spin in brown sugar. Carefully pour cider into glasses. Add one shot of vodka per glass, unless you desire a stronger drink. To top off the drinks you can add a Cinnamon Stick, whipped cream, sprinkle brown sugar and/or add caramel syrup. Please drink responsibly, enjoy!