Boil the jumbo pasta shells until just al dente. Drain and lay them flat so they do not stick together.
Mix the ricotta, mozzarella, Parmesan, egg, garlic, Italian seasoning, paprika, salt, black pepper, and 1 tbsp parsley. Fold in the raw chopped shrimp.
Melt the butter in a saucepan over medium-low heat. Add the garlic and cook for 20 seconds. Whisk in the flour for 1 minute.
Slowly add the heavy cream and whole milk, then stir in the Parmesan, garlic powder, onion powder, salt, and black pepper until smooth and creamy.
Heat oven to 375°F. Spread a little sauce in a greased 9x13 inch baking dish. Fill the shells with the creamy shrimp mixture and place them seam side up in the dish.
Spoon the remaining garlic cream sauce over and around the shrimp stuffed shells. Top with mozzarella and Parmesan.
Cover loosely with foil and bake for 15 minutes. Uncover and bake for 3 to 5 minutes more, until bubbly and the shrimp are fully opaque.
Let the stuffed shells rest for 5 minutes, then sprinkle with parsley. Serve warm.