Preheat your oven to 375°F (190°C).
Cook the lasagna noodles according to package instructions until al dente. Drain and set aside.
In a large skillet, melt 2 tablespoons of butter over medium heat. Add the minced garlic and red pepper flakes, and sauté for about 1 minute until fragrant.
Add the shrimp to the skillet and cook until they turn pink, about 3-4 minutes. Squeeze in the lemon juice and add the zest. Season with salt and pepper. Remove from heat and let cool slightly.
In a mixing bowl, combine the ricotta cheese, Italian seasoning, and half of the Parmesan cheese. Season with salt and pepper.
To assemble the lasagna, spread a thin layer of the shrimp mixture on the bottom of the baking dish. Place 3 lasagna noodles over the mixture.
Spread half of the ricotta mixture over the noodles, followed by half of the shrimp mixture. Sprinkle with a layer of mozzarella cheese.
Repeat this layering with the remaining noodles, ricotta mixture, shrimp mixture, and mozzarella cheese.
Finish with the remaining mozzarella and Parmesan cheese on top. Dot with the remaining 2 tablespoons of butter.
Cover the baking dish with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 20 minutes or until the cheese is bubbly and golden.
Remove from the oven and let it rest for about 10 minutes before slicing. Garnish with chopped parsley before serving.