Preheat the oven: Set oven to 375°F (190°C) and line a baking sheet with parchment paper.
Mix the meatloaf base: In a large bowl, combine ground chicken, breadcrumbs, Parmesan, milk, egg, garlic powder, onion powder, salt, and pepper. Mix just until combined.
Shape and layer: Spread the mixture into a ½-inch thick rectangle on the parchment. Lay ham slices over the surface, then add Swiss cheese.
Roll it up: Roll the mixture into a log using the parchment to guide you. Seal the ends and place seam-side down on the sheet.
Top with sauce: Spoon marinara sauce over the loaf and spread evenly.
Bake: Bake for 45–50 minutes, or until the internal temperature hits 165°F (74°C). The top should be golden and the edges slightly bubbly.
Rest and slice: Let it rest for 5–10 minutes before slicing to help everything set and stay intact.