Preheat the oven to 375°F (190°C). Boil lasagna noodles according to package instructions, then drain and let cool.
Heat olive oil in a large pan over medium heat. Add minced garlic and sauté for about 1 minute until fragrant.
Add shrimp to the pan and cook for 3-4 minutes until pink and opaque.
Stir in crab meat, salt, black pepper, and chili flakes. Cook for 2-3 minutes more, then remove from heat.
In a mixing bowl, combine ricotta, half of the Parmesan, 1 cup mozzarella, chopped parsley, and heavy cream; mix until smooth.
Spread a layer of Alfredo sauce in the bottom of a 9x13-inch baking pan to prevent sticking.
Layer noodles over the sauce, then spread a portion of the cheese mixture, followed by the seafood, and drizzle more Alfredo sauce.
Repeat the layering process to create three layers, finishing with noodles and Alfredo sauce on top.
Sprinkle the remaining Parmesan, mozzarella, and breadcrumb topping evenly over the top layer.
Cover the pan loosely with foil and bake for 25 minutes. Remove foil and bake an additional 10-15 minutes until bubbly and golden brown.
Allow the lasagna to rest for 10 minutes before serving. Garnish with extra parsley if desired.