Preheat oven to 425 degrees Fahrenheit. Line a sheet tray with aluminum foil.
Cut each potato in half, lengthwise, and place on the sheet tray. Rub in 1 tablespoon olive oil, ½ teaspoon salt, ¼ teaspoon pepper, 2 teaspoons garlic herb seasoning, and ¼ teaspoon cinnamon. Make sure it is all evenly incorporated, then place face down and bake for about 40 minutes (depending on size) or until they are very soft and caramelized.
In a small pot, cook quinoa in the broth (instead of water) according to package directions.
In a medium pan, heat up the remaining oil on high heat. Cook onions and peppers for 2-3 minutes until they are caramelized and the onions are translucent. Add the spinach and cook for another minute, until wilted. Lower the heat to medium and add the garlic, beans, cooked quinoa, and corn. Stir in 1 teaspoon garlic herb seasoning, ½ teaspoon salt, ½ teaspoon black pepper, paprika, cumin, crushed red pepper, and chili powder. Cook for 2 minutes then turn off the heat.
Once the potatoes are finished, preheat oven to 400 degrees Fahrenheit.
Scoop out the potato insides into a stand mixer with a paddle attachment, or a potato masher. There should be a thin layer of potato remaining on the skin, enough for it to hold its shape. Mash the potatoes with either a potato masher/ricer or paddle attachment, and add in milk, remaining cinnamon, remaining garlic herb seasoning, remaining black pepper, ½ teaspoon salt, and thyme if using. Mix in the Parmesan and cheddar.
Remove paddle attachment and switch to a spatula. Gently fold in the vegetable/quinoa mixture. Add the remaining salt, only if necessary. Spoon the filling back into the potatoes, then top with fat free cheddar. Bake for 5 minutes. Serve with desired toppings, such as cilantro, lime, avocado, and/or Greek yogurt.