Combine sugar, honey, cider, mustard, paprika and garlic powder in a medium sauce pan and season with salt and pepper. Whisk ingredients together and bring to a simmer. Cook until reduced slightly, about 5-7 minutes.
Place ham in slow cooker and separate slices slightly. Pour glaze over ham and place lid on slow cooker. Basting every hour, cook on low for 4-6 hours depending on size of the ham. Serve with the glaze on the side.