Gather all ingredients.

Preheat the oven to 350 degrees F (175 degrees C).

Bring a large pot of salted water to a boil. Add shells and cook, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain, rinse under cold water, and set aside.

Mix together cottage cheese, mozzarella cheese, 1/2 cup Parmesan cheese, eggs, and garlic powder in a large bowl. Rub oregano and parsley between your palms to pulverize them, then stir into cheese mixture.

Stuff cheese mixture into pasta shells.

Spread 1/3 of the spaghetti sauce on the bottom of a 15x10-inch baking dish. Place shells in the baking dish, seam-side up; they should fit snuggly in a single layer. Spread remaining sauce on top; sprinkle with remaining 1/4 cup Parmesan cheese.

Bake in the preheated oven until bubbly, 25 to 35 minutes. Let stand 10 minutes before serving.