Pizzeria Casserole

I found this recipe years ago from some Smart & Final publication.  Maybe even on the back of one of their products.  The recipe is written for 16 servings, which makes it easy for me to make for swapping purposes because I don't have to do any math.

2/3 c chopped black olives
Parm-Romano cheese blend, to taste
1 tsp salt
1 1/2 c sliced mushrooms
2 lbs. Italian sausage (I used a mix of hot and sweet)
2 c shredded pizza cheese blend
28 oz. tomato strips with basil
1/2 tsp pepper
28 oz. pizza sauce
2 tsp. dried oregano
7 oz. sliced pepperoni
5 c ditalini pasta
1 lge onion, chopped
2 tsp. dried basil

Preheat the oven to 350.  Cook pasta; drain.  Meanwhile, cook sausage and onion over medium heat till meat is no longer pink and is broken up.  Drain.  In large bowl combine pizza sauce and tomato strips.  Stir in sausage mixture, pasta, pepperoni, mushrooms, black olives, basil, oregano, salt & pepper.  Transfer to greased baking dish.  Sprinkle with pizza cheese blend, covering entire dish.  Bake 45 minutes till cheese is golden brown.  Remove and top with Romano cheese blend.

So...of course I had a few substitutes...and omissions.  I did not give you cheese blend for after baking.  I did not add any salt to the dish.  I used regular canned tomatoes with "spice" instead of strips.  I made my own pizza sauce (tomato sauce cooked up with Italian seasoning).  I might have forgot to put in pepperoni?  Oops.  I used rotini pasta instead of ditalini, and because rotini is much larger than ditalini, I used about 4 cups of pasta.  Also, I used WAY more than 2 cups of shredded cheese blend to top the dishes (and did not use pizza cheese blend).   I think I used 2 cups of cheese per Pyrex pan instead of 2 cups total for all 16 servings...the cheese was not covering the pans.  Also, since the dish is meant to be baked up in one big pan, and I divided it up into 3 pans, cooking time takes less than 45 minutes...20-30 is a better guestimate.  Everything is cooked, you're just heating everything through and melting cheese.  Oh and "large" bowl is really an undertatement.  You need a HUGE bowl.  I whipped out my giant Tupperware bowl and it was nearly full when I added all the ingredients.