These classic stuffed shells are made with cooked pasta shells, a cheesy ricotta filling, a few Italian herbs, and plenty of marinara! This cheesy pasta dish is pure comfort food and couldn't be simpler to make.
Bring a large pot of water to a boil. Add a generous amount of salt and then add in the pasta shells. I usually cook a few extra in case some fall apart. Cook for HALF of the time indicated on the package PLUS one minute. (About 5-6 minutes depending on the package you use). Drain the shells and rinse under cold water to stop the cooking and allow them to be easily separated. Drain off any water and separate onto a sheet of parchment paper on the counter.
Preheat oven to 350 degrees Fahrenheit. In a large mixing bowl whisk the egg with a fork. Add in the ricotta cheese and mix together until completely combined. Add in the basil, oregano, thyme, parsley, minced garlic, and salt + pepper to taste. (I use about 1 teaspoon salt and 1/2 teaspoon pepper). Stir gently.
Finely grate the mozzarella and parmesan cheese. Add two cups of the mozzarella and all of the parmesan cheese into the cheese mixture. Gently stir to completely combine.
Transfer this cheese mixture to a large (gallon sized) ziplock bag. Snip off 1-inch of the corner of the bag and "pipe" the cheese mixture into each of the shells. Each shell should get about 2 tablespoons of the cheese mixture (which should fill 25-26 shells).
Grab a 3-quart (9 x 13 inch) baking dish and spread 1/2 cup of marinara sauce evenly across the bottom.
Place stuffed shells in the baking dish with the open side facing up. Pack the shells in close together.
Cover shells evenly with remaining 2 and 1/2 cups marinara sauce. Aim to completely cover all of the shells to avoid hard parts of the shells. Cover with foil and bake for 30 minutes.
Remove foil and add remaining 1 cup of mozzarella evenly over the shells. Return to the oven for 5-7 more minutes or until cheese is melted. Serve warm with freshly chopped basil if desired. I also like to add a little more cracked pepper to the top!