Rinse the squash in cold water, and pat dry with paper towels. With a sharp chef's knife, cut the spaghetti squash in half lengthwise, and with a spoon scoop out the seeds. Place the squash halves in a baking dish or a rimmed baking sheet, cut side up.

Melt a teaspoon of butter in the microwave, and brush it on the inside of the Squash, and bake at 350 for 45 to 50 minutes, or until done. Remove from oven, and cool. 

When the Squash is cool enough to handle, take a fork and shred the inside until the strands appear like spaghetti. Remove the noodle/strands, and place in a dish and set aside.

Place the ground sirloin in a large skillet, sprinkle with garlic salt and seasoned pepper, and cook until well done. This will be the bulk of the filling for the baked spaghetti squash.

Drain grease from meat on paper towels and crumble the meat into a fine crumble. Leave on fresh paper towels to continue draining. 

Chop onion, and place in skillet with a teaspoon of butter, and sauté until onion is slightly browned. Return meat to skillet, and mix in onion.  Add canned tomatoes, and cut into bite size pieces. 

Add tomato paste, and fill the can with water 2 times and add to skillet. Press clove of garlic, and add to skillet. Cut bell peppers into small pieces, and add to skillet. 

Sprinkle Italian seasoning, oregano, sweet basil, seasoning, and brown sugar into skillet, and stir well.  Continue to cook for 30 minutes on medium to medium low.

Add squash strands to skillet, and mix altogether until blended. Remove skillet from stove, and spoon mixture into Squash shells. 

Top the baked spaghetti squash with Parmesan cheese, and bake for 30 minutes, or until cheese is browned and bubbly. Remove from oven, cool slightly and serve with a small salad.