In a medium stockpot, whisk together the chicken broth, kosher salt, black pepper, garlic powder, onion powder, and dried thyme.
Add the butternut squash cubes. Bring to a boil over high heat (this should take about 10 minutes), then lower the heat to medium, cover the pot, and cook until the butternut squash is very tender, about 10 minutes.
Turn the heat off. Puree the soup in batches in your blender or food processor (be careful when handling the hot liquids), or use an immersion blender to puree the soup in the stockpot, as shown in the video below.
Return the soup to the pot. Turn the heat back on to medium-low. Stir in the heavy cream and the Parmesan and cook, uncovered, just until heated through, about 2 more minutes. Taste to decide if you'd like to add a bit more salt, then serve.
If the soup comes out too thin to your liking, you can stir in more cream and/or parmesan (up to ¼ cup more of each). Or make a cornstarch slurry (2 tablespoons of cornstarch mixed with 3 tablespoons of cold water until dissolved), stir the slurry it into the soup, and heat it over medium heat, stirring, until the soup thickens. Another option is to mix ½ tablespoon of coconut flour into the warm soup.