Bring a large pot of salted water to a boil. Cook jumbo pasta shells until al dente, about 8-10 minutes, then drain and rinse under cold water to stop cooking.

In a large skillet, melt butter with olive oil. Sauté garlic until fragrant, then stir in cream cheese and gradually add heavy cream, thickening for about 3-5 minutes.

Combine crab meat, shrimp, ricotta, and mozzarella in a mixing bowl. Add a quarter cup of the sauce mixture to bind, then season with salt and pepper.

Stuff each pasta shell with the seafood filling and place in a greased 9x13 inch baking dish.

Pour the remaining sauce over the shells and sprinkle with grated Parmesan cheese.

Cover with foil and bake at 375°F (190°C) for 20 minutes, then remove foil and bake for an additional 10 minutes until golden.

Garnish with fresh parsley before serving.