Preheat your oven to 350°F (175°C).

Remove the packaging from the ham and place it in a large oven-safe casserole dish.

Interleave the pineapple slices between the layers of the ham and pour reserved pineapple juice over the top.

Sprinkle brown sugar evenly across the ham and pineapple slices.

Cover the dish with aluminum foil and bake for approximately 1.5 hours.

Halfway through, remove the foil and baste the ham with pan juices.

Once done, let the ham rest for a few minutes before slicing and serving.