Arrange the frozen rolls on a sheet of wax paper on the counter. Thaw for 20-30 minutes, then quarter the rolls using a sharp knife.
In a large skillet, cook the sausage and minced onion until no pink remains. Drain all excess fat from the pan. Set aside to cool, or this can be done in advance and chilled, if preferred.
Into a gallon-sized plastic storage bag, shake together the grated parmesan cheese, dry Italian seasoning, garlic powder, onion powder and garlic salt.
Toss the bread pieces in the melted butter then add to the cheese mixture. Seal and shake until coated.
Spritz the bottom and sides of a non-stick 9 x 13-inch baking pan with cooking spray. Arrange 1/2 of the quartered rolls on the bottom of the pan. At this point, they won't touch, the bread still has to rise.
Over the rolls, sprinkle 1/3 of the shredded mozzarella cheese, 1/2 of the asiago cheese and 1/2 of the crumbled sausage.
Repeat, ending with the final 1/3 of shredded mozzarella cheese and asiago.
Cover the plastic wrap and allow the rolls to rise in a draft-free place until doubled. Around 1.5 - 2 hours.
Uncover and bake at 375 degrees for 35-40 minutes or until puffy and golden.
Pull apart and serve with warmed pizza sauce for dipping.