Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.

In a medium mixing bowl, combine the thoroughly dried spinach, crumbled feta cheese, softened cream cheese, and minced garlic. Mix until evenly incorporated.

Unroll the thawed puff pastry sheets onto a clean, lightly floured surface. Cut each sheet into 9 equal squares.

Place approximately one tablespoon of the spinach and cheese mixture into the center of each puff pastry square.

Fold the four corners of each pastry square into the center over the filling. Pinch the edges together slightly to seal them into little pouches.

Transfer the pastries to the prepared baking sheet. Lightly brush the tops and sides of the pastry with the beaten egg wash.

Bake for 15-20 minutes, or until the pastries are puffed and beautifully golden brown. Let cool for 5 minutes before serving.