Preheat your oven to 375°F (190°C) and lightly grease a small individual-sized baking dish.
Bring a pot of salted water to a boil and cook the lasagna noodles until al dente, then drain and set aside.
In a non-stick skillet over medium heat, brown the ground beef until fully cooked, breaking it into small crumbles.
Season the beef with garlic powder, dried oregano, sea salt, and black pepper.
Add the fresh baby spinach to the skillet and sauté for 1-2 minutes until just wilted, then remove from heat.
In a small bowl, stir the ricotta cheese with one tablespoon of the marinara sauce to create a creamy consistency.
Spread a thin layer of marinara sauce on the bottom of the baking dish, followed by a piece of noodle.
Layer half of the beef and spinach mixture, half of the ricotta mixture, and another spoonful of sauce.
Repeat the layers with the remaining noodle, beef, ricotta, and sauce, finishing with a sprinkle of mozzarella cheese.
Bake for 15-20 minutes until the cheese is melted and the edges are bubbling.