Preheat oven to 450°F.

Cover a large baking sheet pan with foil, then spray the foil with a cooking spray, place washed potatoes onto sheet pan. Roast potatoes for 30-40 minutes, or until potatoes are fork tender.

Using a potato masher or a large serving fork, sprayed with cooking spray, press the potatoes so that they flatten and break open. It's okay if they break apart a little.

Put garlic, red pepper flakes, and butter in a small microwave-safe bowl, and microwave for 30 seconds, or until butter is melted. Brush tops of potatoes with half of the garlic butter, generously and evenly.

Roast potatoes for about 10-15 minutes or until tops start to turn golden brown and crispy.

Brush the rest of the butter onto the potatoes then sprinkle the potatoes with parmesan and place back into the oven. Turn the broiler on low heat (or high, if you watch cautiously) for 2-5 minutes or until cheese is melted and browned a little.

Remove potatoes from oven. Garnish with parsley and remaining cheese, then season with salt and pepper to taste. Let potatoes cool slightly before serving.