Preheat your oven to 350°F (175°C) and prepare a baking dish with nonstick spray.

In a skillet over medium heat, add olive oil, onions, and garlic. Sauté until onions are translucent (3-5 minutes).

Add spinach and artichokes; cook until spinach wilts (2-3 minutes).

Lower heat and mix in cream cheese until melted; stir in reserved pasta water to achieve desired creaminess.

Combine cooked pasta with the creamy mixture, adding 1½ cups mozzarella and seasonings.

Transfer to the baking dish; top with remaining mozzarella and Parmesan. Bake for 25-30 minutes or until golden brown.