Rinse, core, and slice apples, or use an apple slicer. It’s okay to leave the skin on the apples.
If possible, use whole spices for this recipe: one nutmeg seed and two allspice berries. Crack the seeds and berries open with a mortar and pestle.
Place the apples in a slow cooker along with the brown sugar, nutmeg, allspice, and cinnamon sticks.
Cover apples with water, with approximately 6 cups of water for a 6-quart slow cooker. The amount of water will vary depending on the size of your slow cooker.
Cover the slow cooker and cook on high for 5-6 hours.
After the initial cook time, uncover and mash the apple with a large potato masher until the fruit is well mashed.
Cover and cook on high for an additional 1 hour.
Let the cider cool to a temperature you can easily work with to strain.
Strain the thick apple mixture very slowly through a fine mesh strainer into a large stockpot or deep bowl. Add cheesecloth to the strainer to get a smoother finished cider.
Remove the solids from the strainer and do a second strain to catch any remaining solids.Pour into a heat-proof pitcher or ladle into cups. Cider is ready to serve, warm, accompanied by slices of apple and a cinnamon stick for garnish.