If you are using frozen puff pastry remove a sheet from the freezer and let it sit out for 15 - 20 minutes.
In a bowl combine the olive oil, Parmesan cheese, garlic powder, parsley, salt, and pepper.
Take your puff pastry sheet and roll it out slightly. This is just to flatten it a little so 2 passes of the rolling pin should be plenty.
Spread the Parmesan mixture over the puff pastry leaving a little in the bowl to brush the top with later.
Sprinkle the cooked pancetta over the puff pastry.
Gently roll the puff pastry up starting on a long side to create a long roll.
Cut the roll into pieces about 2 inches thick.
Place the rolls on a parchment paper lined baking sheet and brush the tops of each roll with the last of the Parmesan mixture.
Bake for 35-40 minutes or until the puff pastry looks fully cooked in the middle of the pinwheel spiral. Note: After the first 20 minutes check the pinwheels often to make sure that they aren't overcooking on the bottoms.