You can sub cottage cheese for the ricotta if desired, also the shells can be cooked and stuffed then refrigerated until ready to bake later in the day, and you can use fresh broccoli in place of the frozen. This is a great manicotti dish!
Cook the manicotti shells until firm-tender (careful not to overcook, leave fairly firm) drain.
In a large bowl, combine the ricotta or cottage cheese (if using) broccoli, 1 cup of mozza cheese, 1/4 cup Parmesan cheese, egg, parsley, onion powder, salt, pepper and garlic powder; mix well to combine and set aside.
In a skillet cook the crumbled sausage meat over medium heat until no longer pink; drain fat.
Add in the pasta sauce and minced garlic (if using), cook over medium heat for about 5-8 minutes.
Spread about 1-1/2 cups of the pasta/sausage mixture in the bottom of prepared baking dish.
Stuff the manicotti shells with the broccoli mixture (careful not to overstuff as the shells will tear).
Arrange the stuffed shells over the sauce.
Top with remaining sauce.
Then sprinkle with remaining Parmesan cheese, then top with remaining mozza cheese.
Set oven to 350 degrees.
Bake the shells for about 40-50 minutes, or until heated through.