In a mixing bowl, combine softened cream cheese, grated Parmesan, mayonnaise, garlic powder, onion powder, and black pepper until well combined.

Squeeze out any excess moisture from the thawed spinach and add it to the cream cheese mixture. Blend until uniform.

On a lightly floured surface, roll out the puff pastry and spread the spinach mixture evenly over the pastry, leaving one long edge clear to help seal the log.

Carefully roll the pastry like a jelly roll, keeping it tight and even. Wrap the log in plastic wrap and refrigerate for about 30 minutes.

Preheat your oven to 400°F (200°C).

Once chilled, slice the log into half-inch rounds and lay them on a baking sheet lined with parchment paper.

Brush the tops of the pinwheels with the beaten egg.

Bake for 15-20 minutes, or until puffed and golden brown.