Step 1: Preheat your oven to 375°F (190°C) and lightly grease a baking dish that fits the peppers snugly.
Step 2: Rinse the quinoa thoroughly in a fine-mesh sieve. In a medium saucepan, combine quinoa and vegetable broth. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes until liquid is absorbed.
Step 3: While the quinoa cooks, slice the tops off the bell peppers and remove the seeds and membranes. Finely chop the edible parts of the pepper tops to include in the filling.
Step 4: In a large skillet, heat the olive oil over medium heat. Add the onion, chopped pepper tops, and diced butternut squash. Sauté for 8-10 minutes until the squash is tender.
Step 5: Stir in the garlic, dried cranberries, sage, and smoked paprika. Cook for another 2 minutes until fragrant.
Step 6: Combine the cooked quinoa and the sautéed vegetable mixture in a large bowl. Season with salt and pepper, and stir in the fresh parsley.
Step 7: Spoon the filling generously into each hollowed-out bell pepper. Place the peppers upright in the prepared baking dish.
Step 8: Cover the dish with foil and bake for 30 minutes. Remove the foil and bake for an additional 10-15 minutes until the peppers are soft and slightly browned.
Step 9: Let the peppers rest for 5 minutes before serving to allow the flavors to meld.