In a bowl, combine the cream cheese, Parmesan, mayonnaise, garlic powder, onion powder, and black pepper. Add in the spinach and mix until smooth and evenly combined.

Lightly flour your countertop and roll out the puff pastry. Spread the spinach mixture across it, leaving one long edge empty to seal later. Roll it tightly like a jelly roll.

Wrap the log in plastic wrap and refrigerate for 30 minutes to firm up. Preheat your oven to 400°F while waiting.

Remove the log from the fridge and slice it into half-inch rounds. Place them on a parchment-lined baking sheet.

Beat the egg with a splash of water and brush it on top of each pinwheel.

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