Preheat your oven to 375°F (190°C) and lightly grease a small individual-sized baking dish.
Boil the whole wheat lasagna noodles in salted water until al dente, then drain and set aside.
In a skillet over medium heat, add the olive oil and brown the ground beef until fully cooked, seasoning with half of the sea salt and black pepper.
Stir the marinara sauce into the cooked beef and let it simmer for 2 minutes to meld the flavors.
In a small bowl, combine the ricotta cheese, whisked egg, dried oregano, garlic powder, and the remaining salt and pepper.
Place a small amount of meat sauce at the bottom of the baking dish, then top with a layer of noodles (cut to fit if necessary).
Spread half of the ricotta mixture over the noodles, followed by a layer of fresh baby spinach and more meat sauce.
Repeat the layers, finishing with a final layer of meat sauce, mozzarella cheese, and grated parmesan.
Cover with foil and bake for 20 minutes, then remove the foil and bake for another 5-10 minutes until the cheese is bubbly and golden.
Let the lasagna rest for 5 minutes before serving to allow the layers to set.