Searching for a brand-new fall treat this year? Try these Pumpkin Doughnut Muffins! They combine the warm flavors of pumpkin, cinnamon, and nutmeg with a soft, cake-like texture. Rolled in cinnamon sugar for an ideal completing touch, these muffins are simple to make and even simpler to enjoy. Brought to you by Martha Stewart: Subscribe for more Martha now: Want more Martha? Twitter: Facebook: Pinterest: Instagram: Google Plus: Martha's Official Blog site: . The Martha Stewart channel…