Pre-heat oven to 350°F.
In a medium saucepan, brown ground beef, onion and bell pepper.
Add pepperoni and sauce.
In a separate saucepan, boil pasta for 10 minutes; drain.
Add to meat sauce mixture.
In a medium bowl, mix 2 cups of mozzarella, the cottage cheese, and Italian Seasoning.
In a 9 × 13-inch baking dish, layer almost ½ of pasta/meat mixture.
Then, add a layer of ½ cheese mixture.
Add another layer of pasta/meat (make sure to leave enough for a thin third layer).
Add a layer of the rest of the cheese mixture.
Top with remaining pasta/meat, and sprinkle on the ½ cup of mozzarella.
Bake for 35 minutes.