Set Instant Pot to saute mode and heat olive oil. Add chopped onions and saute for 2 minutes.

Add minced garlic, rosemary sprigs, and red pepper flakes; cook for 1 minute.

Add butternut squash, kosher salt, and vegetable broth. Stir well. Close the Instant Pot with the pressure release valve set to sealing. Pressure cook for 8 minutes followed by quick release.

Remove rosemary sprigs. Add cream cheese and blend until the soup is creamy and smooth. Adjust seasoning with more salt and black pepper if needed.

Serve hot, garnished with pumpkin seeds.