Score the fat cap of the ham in a crosshatch pattern, cutting about 1/4 inch deep into the fat layer.

Pour 1/2 cup bourbon into a small saucepan over medium heat. Let simmer for 2-3 minutes to burn off harsh alcohol.

Mix the reduced bourbon with pure maple syrup, brown sugar, Dijon mustard, butter, and apple cider vinegar to create the glaze.

Place scored ham fat-side up in slow cooker. Pour apple cider vinegar and water (1/2 cup each) on the bottom for steam.

Set slow cooker to LOW. Plan on approximately 1 hour per pound (10 lbs = about 10 hours of cooking).

Starting at hour 4, brush glaze over the ham every 30-40 minutes using a pastry brush to build caramelized layers.

Use an instant-read thermometer to check internal temperature. Ham is ready when it reaches 140°F.

Remove ham from slow cooker carefully and let rest for 15 minutes before carving.

Carve ham into thick slices, allowing glaze and accumulated juices to drip over the meat.

Serve warm with reserved glaze drizzled over slices. Refrigerate leftovers up to 3-4 days, or freeze up to 2 months.