Add a thin layer of brown sugar to the bottom of your slow cooker. Place the ham on top of the brown sugar, cut side down. Sprinkle additional brown sugar across the top of the ham.
Cover the Crock-Pot. If the ham is too tall to fit completely inside, make a tinfoil hat for it by layering a couple of pieces of tinfoil across the top of your slow cooker and crimping around the edges to completely cover. Lay a dish towel on top of the foil to help keep it weighed down and prevent heat from escaping.
Cook ham on low for 5-6 hours. Flipping the ham over and basting halfway through will help prevent it from drying out on top, but it's not strictly necessary.
That's it! Carve your ham (reserving the ham bone to make broth), trim fat, and serve.
Two ingredients is really all you need for a tasty ham (and all I used here), but if you'd like you can either add in some canned pineapple, or make a brown sugar-mustard-honey glaze rather than using straight brown sugar. My ham here cooked for 5.5 hours and was perfectly done, but I did lose heat by opening the foil to flip it halfway through.
How to Make Ham in a Crock-Pot from Mashup Mom: https://www.mashupmom.com/how-to-make-ham-in-a-crock-pot-an-easy-two-ingredient-recipe/