Add bacon to a large pot over medium heat. Cook until crisp, then remove from pot (leaving the fat) and set aside. Coarsely chop bacon once cooled.
Add diced onion to reserved bacon fat, and sauté until softened, 3-4 minutes. Add garlic and red pepper, and cook for an additional minute.
Add broth, pumpkin puree, and spices (paprika, cumin, cinnamon, cayenne, pumpkin spice, salt, and pepper) to pot and stir to combine. Simmer for about 15 minutes.
Process soup with an immersion blender (or in batches with a standard blender) until smooth.
Reduce heat to medium low. Stir in cream and sweetener. Simmer until heated through. Season with additional salt and pepper to taste.
Serve hot, topped with the chopped bacon. Additionally garnish with toasted pumpkin seeds, a drizzle of cream, and/or a dollop of sour cream if desired.