Preheat oven to 375°F. Spray small rimmed baking sheet with cooking spray.
Scrub potatoes and slice off any imperfections. Pat dry. Place on baking sheet.
Smash garlic cloves with side of large knife to loosen peel and release flavor. Place garlic in pan with potatoes. Pour melted butter over top of potatoes. Stir to blend flavors. Sprinkle with salt and parsley.
Bake at 375° for 45 minutes to 1 hour.
Remove potatoes to a bowl. Squeeze cooked garlic onto potatoes as well as browned butter and parsley bits. Mix flavors together and serve warm.