Set your Instant Pot to "Sauté" mode and melt the butter. Add the diced onion and cook for 3-4 minutes until softened and fragrant.
Add the minced garlic and cook for another 30 seconds, stirring constantly so it doesn't burn.
Add the cubed butternut squash, chopped apple, vegetable broth, cinnamon, nutmeg, ginger, salt, and pepper. Give everything a good stir.
Cancel "Sauté" mode, secure the lid, and set the valve to "Sealing." Cook on high pressure for 10 minutes.
When the cooking time is complete, carefully quick-release the pressure. Remove the lid and let it cool for a few minutes.
Use an immersion blender to puree the soup until completely smooth and creamy. (If you don't have an immersion blender, carefully transfer the soup in batches to a regular blender.)
Stir in the maple syrup and heavy cream, then taste and adjust seasonings as needed. Serve warm with a drizzle of cream, pumpkin seeds, and fresh thyme if desired. Absolutely delicious!