Cook the pasta: Boil the shells in salted water until slightly undercooked. Shock them in ice water and drain.
Prepare the filling: Strain the ricotta and combine with lemon zest, juice, eggs, Parmesan, basil, and garlic. Season to taste.
Stuff the shells: Use a piping bag or spoon to carefully fill each pasta shell with the ricotta mixture.
Assemble and bake: Spread marinara sauce in a baking dish, arrange the stuffed shells, top with a mixture of cream and butter, and bake at 375°F for 25-30 minutes.
Optional: Broil for 2-3 minutes to get a golden top.
Notes
Variations: Add spinach to the ricotta mixture for extra nutrition or swap the marinara for a creamy Alfredo sauce.
Freezing: You can freeze the unbaked shells for up to 3 months. Just bake them from frozen, adding a few extra minutes to the baking time.