Preheat oven to 400°F and line a sheet pan with foil or parchment paper. Spread the squash cubes on the pan and roast for 20 minutes, or until the edges of the cubes are light brown. Remove from the oven and let cool a bit.
in the blender
Add the squash, apple juice, broth, pumpkin puree, and brown sugar to the blender jar. Puree until smooth. You might have to scrape down the jar during processing. If too thick, add 2 tablespoons of broth or water and process again. Set aside.
for the soup
Heat the oil in a 4 quart Dutch oven or stock pot over medium heat until shimmering. Add the onions and saute until they're soft and transparent. Sprinkle the cinnamon, curry powder, ginger, and salt over the onions, and stir for a minute or two to bloom the spices.
Pour the squash mixture into the onions and bring to a gentle simmer for 10 minutes (keep an eye on the soup — it's likely to sputter). Reduce heat to low and let stand for a few minutes to cool slightly. Add the cream cheese** and dairy, stirring until completely incorporated.
Now, test for thickness: if you'd like a "soupier" soup, add more broth or water by the tablespoon, until it reaches your desired consistency. Taste, and add more salt if necessary.
To serve, ladle into bowls and top with pepitas, or a swirl of heavy cream.
Video
Notes
*If you're buying a whole squash, the weight of the fruit will vary because of the size of the seed pod. Try for two to three pounds. If you have extra flesh, it freezes beautifully. Note also that most grocery stores now carry pre-cubed butternut squash for convenience.** Note that certain dairy products such as cream cheese tend to break in hot soups. To avoid this, whisk the softened cream cheese with a ladle full of the soup in a small bowl until very smooth, then add to the soup.