Preheat oven to 400.

Line a baking sheet with parchment paper and place tomatoes 1/3 of pan.  Put onions on 1/3 of pan and put sausage links on remaining 1/3 of pan.

Drizzle tomatoes and onions with olive oil and season with salt and pepper. Place pan in oven at 400 for 8 minutes, turn sausage over, and continue to roast for 7 more minutes. Remove sausage and drain on paper towels. Return vegetables to oven for 5 more minutes or until tomatoes burst.

While vegetables and sausage are cooking, put marinara in a sauce pan and heat. Season with salt, pepper, sugar, garlic powder and Italian seasoning. Simmer sauce for 20 minutes to blend flavors.

Cut bread into 6 inch lengths, and cut in half leaving roll attached at one side. Spread inside of rolls with butter and sprinkle with garlic powder, and a generous amount of Parmesan cheese.  Toast or broil until bread is toasted. Place 3 links inside each roll. Top each roll with roasted tomatoes and onions. Cover with sauce and sprinkle more cheese on top. Makes 2 sandwiches

Serve immediately