Bring a large pot of salted water to a boil. Add your shells and cook them just until slightly underdone. This is important. If you fully cook them now, they’ll turn too soft in the oven.

Drain them carefully and lay them out so they don’t stick together.

In a large bowl, mix ricotta, mozzarella, Parmesan, one egg, garlic, and herbs. Stir until smooth and creamy.

If you’re adding spinach, cook it first and squeeze out excess moisture. Trust me, skipping this step leads to watery filling.

Spread a layer of marinara sauce on the bottom of your baking dish. This prevents sticking and adds flavor from the bottom up.

Take each shell and gently fill it with the cheese mixture. Don’t overfill. You want them full but not overflowing.

Place them open-side up in the dish.

Pour more marinara over the shells and sprinkle extra mozzarella on top. This is what creates that golden, bubbly finish.

Cover with foil and bake at 375°F for about 25 minutes. Then remove the foil and bake another 10 minutes until the cheese is melted and slightly golden.

Let the dish sit for about 5 minutes. This helps everything set and makes serving easier.