Preheat your oven to 375°F (190°C).
Cook the whole wheat lasagna noodles in a pot of boiling water until al dente, then drain and set aside on a non-stick surface.
In a medium skillet over medium-high heat, add the olive oil and brown the ground beef until cooked through, breaking it into small crumbles.
Stir the tomato puree, dried oregano, garlic powder, sea salt, and black pepper into the beef and simmer for 5 minutes.
In a small bowl, combine the part-skim ricotta cheese with the finely chopped fresh parsley.
Spread a thin layer of the meat sauce on the bottom of a small oven-safe baking dish.
Place one lasagna noodle over the sauce, then layer with half of the ricotta mixture, half of the fresh spinach, and a portion of meat sauce.
Repeat the layers with the remaining noodle, ricotta, and spinach, then top with the remaining meat sauce.
Sprinkle the shredded mozzarella cheese evenly over the top layer.
Cover the dish with foil and bake for 20 minutes, then remove the foil and bake for an additional 10 minutes until the cheese is melted and bubbling.