Cheesy Zucchini Salami Casserole *THE BEST*

My brother-in-law's girlfriend has been telling me about how good this casserole is for a few weeks now and since I've got squash and zucchini coming out of my ears right now I've been sharing it with them.
Well, the other day my BIL returned with a casserole in his hands.
Yep! It was THE casserole she's been raving about.
Oh my!
I can't even begin to describe how good it was.
Hubby, who is a non-zucchini eating person even ate it 
and said, " That's good!"

Cheesy Zucchini Salami Casserole

1 onion, sliced thin
zucchini, sliced thin lengthwise
8 oz. shredded mozzarella
1 cup shredded Parmesan (optional)
2 cups diced salami
1 can of crescent rolls

Layer onion slices in the bottom of a greased 13 X 9.
Place zucchini slices on top of onions.
Sprinkle with cheeses.
Add another layer of zucchini.
Followed by another layer of cheeses.
Top with diced salami.
Place crescent rolls flat on top of casserole.
Bake at 375 degrees for 45 minutes until top is golden brown.

*Additional Note*
I originally posted this recipe with just one layer of zucchini but the last time I made it I made it with a second layer and it was even better. Either way works...you'll just have a thinner or thicker dish depending on the amount of layers you choose.
Enjoy!