Place the butter into a 3 QT saute pan or walled skillet with a cover and melt over medium heat. Add the onions and saute for a few minutes until tender. Add the cubed squash and pour the broth over it. Cover the pan and increase the heat to high to bring to a boil. Reduce the heat to low and simmer, covered, for 10-15 minutes until the squash is very tender.

Transfer the squash to a colander and drain until no excess liquid remains. Transfer the drained squash to the bowl of a stand mixer or a large mixing bowl (if using a hand mixer or immersion blender). Add the marjoram, pepper, cinnamon, and cayenne. Beat the squash (or blend with an immersion blender) until smooth. Taste and decide if you want a bit more cinnamon, a touch of salt, etc.