Preheat oven to 350°F.

Brown ground turkey with garlic and onions over medium-high heat. Add in tomatoes, crushed red pepper, Italian seasoning, and ground black pepper. After a few minutes, add in pasta sauce and simmer, reducing heat to medium-low.

Partially cook the lasagna noodles, boiling for 3-4 minutes.

In a small mixing bowl, mix together egg, ricotta, cup of mozzarella, spinach, and half teaspoon Italian seasoning.

Pour 1/3 of the meat sauce into the bottom of a greased loaf pan. Cover with two lasagna noodles, trimming ends if needed. Spread 1/3 of the cheese mixture on top of the noodles. Cover with meat sauce. Repeat noodles, cheese, and sauce for two more layers. Top the last layer of sauce with the remaining mozzarella cheese.

Cover loaf pan loosely with parchment paper or aluminum foil and bake for 20 minutes. Remove parchment paper and cook for an additional 15 minutes.