Preheat oven to 400 degrees.
Combine ground beef with eggs, breadcrumbs, and seasonings (oregano, garlic powder, and salt). Careful not to overwork the mixture, stir only until combined.
On a cookie sheet lined with foil, shape the meatloaf mixture into a skull shape. Dice onion to form teeth and eyes. Place onions on the meatloaf then wrap the other sections of the skull with bacon.
Whisk together the ketchup, brown sugar, and hot sauce. Brush half of the mixture onto the meatloaf.
Bake until the bacon has rendered, approximately 45 minutes to an hour. Brush with remaining ketchup glaze. Cover the bacon with the slices of provolone and baked until slightly melted, roughly 10-15 minutes.