In medium pot put water to boil and add pasta cook until soft (10 to 12 minutes) keep pasta water aside for sauce and drain pasta.
In large pan add butter and onions and sweat until translucent about 3 mins on medium high heat.
Add garlic, garlic and onion powder pepper and parm cheese. Add shrimp and cook until they start to turn pink.
Add pasta water and coat everything in sauce.
Add fully cooked pasta to pan with spinach and the cherry tomatoes turn to medium low heat to prevent burning.
Add mozzarella cheese and make sure shrimp are fully cooked.
Add chilli flakes if desired dish put the pasta and top with any remaining parm and enjoy!