Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch casserole dish.

Bring a large pot of lightly salted water to a boil. Place pasta in the pot, cook for 8 to 10 minutes, until al dente, and drain.

Cook sausage in a skillet over medium heat until evenly browned.

Combine cooked pasta, sausage, and pasta sauce in the prepared casserole dish. Mix cottage cheese, olives, and mozzarella cheese in a bowl; spoon over sausage and pasta mixture. Top with pepperoni slices.

Bake in the preheated oven until bubbly and lightly browned on top, about 25 to 30 minutes.