Preheat your oven to 400 degrees F and line two baking trays with parchment paper or silicone baking mats.
In a medium mixing bowl, combine softened cream cheese, grated parmesan cheese, garlic powder, onion powder, Italian seasoning, 1 egg, and salt and pepper.
Add your frozen spinach into a bowl of hot water and let sit for 2 minutes. Drain off the water, then squeeze the spinach really well to remove any excess liquid.
Add the spinach into the cheese mixture and mix to combine, then set aside for later.
Working with 1 sheet at a time, unroll the sheets of thawed puff pastry and cut each sheet into 9 equal squares.
Turn each pastry square so it looks like a diamond, then spoon the filling in the middle of the pastry from top to bottom, making sure to leave about half an inch of pastry on each side.
Place on your prepared baking sheets, then lightly brush whisked egg on the right corner of the pastry.
Fold the left pastry corner over the filling, then fold the egg-washed corner over the first folded piece of dough and press gently to seal.
Brush each pastry lightly with the remaining whisked egg and sprinkle with more grated parmesan cheese. Bake for 18-20 minutes, or until golden brown!