Preheat your oven to 375°F (190°C).

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

In a separate bowl, mix together mozzarella cheese, Parmesan cheese, and spinach if desired.

Flatten the meat mixture into a rectangle about ½ inch thick.

Spread the cheese and spinach mixture evenly over the meat, leaving space around the edges.

Roll the meatloaf up jelly-roll style, pinching the ends and seam closed.

Place the stuffed meatloaf seam-side down on a baking sheet.

Bake in the preheated oven for 45-50 minutes until the internal temperature reaches 160°F (71°C).

In the last 10 minutes of baking, spread marinara sauce on top of the meatloaf.

Let the stuffed meatloaf rest for 10 minutes before slicing.

Serve with additional marinara sauce and your choice of sides.