Preheat the oven to 350 degrees F (175 degrees C).
In a medium bowl, mix together the ground beef, bread crumbs, eggs, and onion. Season with garlic powder, salt and pepper. Pat the meat mixture out onto a piece of waxed paper, and flatten to 1/2 inch thick. Lay slices of ham onto the flattened meat, and top with slices of cheese. Pick up the edge of the waxed paper to roll the flattened meat up into a log. Remove waxed paper, seal the ends and seam, and place the loaf into a 9x5 inch loaf pan.
Bake for 1 hour and 15 minutes in the preheated oven, or until the loaf is no longer pink inside.