Preheat your oven to 375°F.
Cook the lasagna noodles in a pot of boiling water until al dente, then drain and set aside.
In a non-stick skillet over medium heat, brown the ground turkey sausage until fully cooked and crumbled.
In a small mixing bowl, whisk together the ricotta cheese, egg whites, dried oregano, garlic powder, sea salt, and black pepper until smooth.
Spread two tablespoons of the marinara sauce across the bottom of a small oven-safe baking dish.
Place half of a lasagna noodle over the sauce, trimming to fit if necessary.
Spread half of the ricotta mixture over the noodle, then layer with half of the fresh spinach and half of the cooked sausage.
Add another layer of marinara sauce and repeat the process with the second half-noodle, remaining ricotta, spinach, and sausage.
Top with the final half-noodle, the remaining marinara sauce, and the shredded mozzarella cheese.
Bake for 20 to 25 minutes until the sauce is bubbling and the cheese is melted and golden.