Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine the ground beef, breadcrumbs, eggs, garlic powder, onion powder, Italian seasoning, salt, and pepper. Mix until just combined.

In another bowl, mix the mozzarella, Parmesan, and optional spinach until creamy.

Flatten half of the meat mixture into a rectangle, add the cheese filling, then roll it tightly, sealing edges.

Place the rolled meatloaf seam-side down on the baking sheet. Bake for 45-50 minutes or until the internal temperature reaches 160°F (71°C).

In the last 10 minutes of baking, spread marinara sauce over the top and return to the oven.

Let the meatloaf rest for 10 minutes before slicing.

Serve warm, sliced, with remaining marinara sauce.