Heat olive oil in a large pot over medium heat. Add the butternut squash, onion, bell pepper, and celery. Sprinkle with salt and cook for 10-12 minutes, stirring occasionally.

Add the garlic, paprika, thyme, rosemary, cayenne pepper, cumin, and additional salt and pepper. Stir and cook for 2 minutes.

Pour in the stock. Bring to a boil, then reduce heat and simmer for 20 minutes, until vegetables are tender.

Blend the soup until smooth using an immersion blender or regular blender. Adjust seasoning and consistency as needed.

Simmer the soup for 5 more minutes to develop flavor.

Serve hot, garnished with toasted pepitas, red chili flakes, and parsley if desired.