In a large pot, heat the oil over medium heat. Add the red onion and bell pepper and cook, stirring frequently, until the onion is softened, about 5 minutes.
Adjust heat to medium-low and add the sweet potatoes, carrots, garlic, nutritional yeast, smoked paprika, garlic powder and cumin.
Cook 5 more minutes, adding 1-2 Tbsp water if needed. Stir in the vegetable broth, water and quinoa, cover and bring to a boil over medium high heat.
Once boiling, adjust the heat so that the soup is simmering, cover and cook, stirring occasionally, until the quinoa is tender, about 20 minutes.
Puree half the soup using an immersion blender, or transfer to a high speed blender. Add the spinach, stirring to split up clumps, and salt to taste.
Let the soup cool 20 minutes. Top with pepitas and cilantro. Serve with a slice of crusty bread. Store in the fridge up to 7 days.