Preheat your oven to 400°F. Line a baking sheet with parchment paper.
In a large bowl, combine the chopped spinach, feta cheese, ricotta cheese, Parmesan cheese, garlic powder, black pepper, and salt. Mix until well combined.
On a lightly floured surface, roll out each sheet of puff pastry to smooth out creases. Cut each sheet into 6 equal rectangles.
Spoon a generous amount of the spinach and cheese mixture onto one half of each rectangle. Fold the other half over and press the edges to seal. Use a fork to crimp the edges for a decorative touch.
Place the twists on the prepared baking sheet. Brush the tops with the beaten egg and sprinkle with sesame seeds if desired.
Bake for 20-25 minutes, or until golden brown and puffed. Allow to cool for a few minutes before serving.