Preheat your oven to 375°F (190°C).
Cook the lasagna noodle in a pot of boiling salted water until al dente, then drain and set aside.
Heat olive oil in a skillet over medium heat and brown the ground beef until fully cooked.
Season the beef with sea salt, black pepper, garlic powder, and dried oregano.
Add the fresh spinach to the skillet and sauté for 1-2 minutes until wilted, then remove from heat.
In a small bowl, stir the ricotta cheese until it reaches a smooth, spreadable consistency.
Spread 2 tablespoons of tomato sauce on the bottom of a small oven-safe baking dish.
Cut the cooked lasagna noodle in half to fit the dimensions of your dish.
Place one half-noodle down, followed by half of the beef and spinach mixture, half of the ricotta, and a layer of sauce.
Repeat the layers with the remaining noodle, beef mixture, ricotta, and sauce.
Sprinkle the shredded mozzarella and parmesan cheese evenly over the top.
Bake for 15-20 minutes until the cheese is melted and the edges are golden and bubbly.