Cook the pasta: Bring a large pot of well-salted water to a boil, add 1 tablespoon of olive oil. Add the pasta and cook it 2 minutes shorter than the recommended time on the package. Stir the pasta from time to time with a wooden spoon making sure it doesn't stick to the pot. Drain, toss with cold water and drain again.
Preheat the oven to 375°F/190°C/Gas Mark 5, no fan.
Make the filling: add all the filling ingredients into a large bowl (well-drained cottage cheese, grated Parmesan, shredded mozzarella, Italian herbs, basil, onion and garlic powder, egg), stir until combined, season with salt and pepper.
Spread the marinara sauce in a 9x13-inch (22x32cm) casserole dish.
Fill each pasta shell with the cheese filling. Arrange the shells with the stuffing side up in the baking dish.
Top the shells with remaining mozzarella cheese.
Cover the baking dish with aluminum foil and bake for 30 minutes.
Uncover the dish and put it under the broiler. Bake for 3-5 minutes or until the cheese is browned (keep an eye on it, it can burn quickly).
Take out of the oven and let rest for 10 minutes (the sauce will thicken).
Enjoy!