In a mixing bowl, combine softened cream cheese, Parmesan cheese, mayonnaise, garlic powder, onion powder, black pepper, and thoroughly dried spinach. Blend until smooth and creamy.

On a floured countertop, roll out the thawed puff pastry into a rectangle, about ¼ inch thick. Spread the filling evenly over the pastry, leaving about an inch border on one side. Roll tightly and seal the edge.

Wrap the log in plastic wrap and refrigerate for at least 30 minutes.

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

Once chilled, unwrap the log and slice it into half-inch rounds. Brush the tops with a beaten egg.

Bake in the preheated oven for 15–20 minutes until golden brown. Allow to cool slightly before serving.