Preheat oven to 400°F. Divide the butternut squash between 2 baking sheets lined with parchment paper, spreading it out so that the pieces are not touching. Roast for 25–30 minutes or until fork tender, flipping halfway through to ensure even caramelization and avoid burning.

Allow squash to cool completely, then place on a sheet pan and freeze, uncovered, for 2 hours. Transfer to a freezer-safe container or bag and freeze overnight. (If stored properly, squash may be frozen for up to 6 months.)

Just before you plan to serve the ice cream, break apart the chunks of frozen squash and add them to a high-speed blender or food processor along with 1/2 cup coconut milk, cinnamon, vanilla, salt, and maple syrup (if using). Blend, pausing frequently to scrape down the sides. Slowly add up to another 1/2 cup coconut milk, if needed, to get a creamy, thick, soft-serve consistency. Be careful not to overblend or you will wind up with soup instead of ice cream.

Note: Blend ice cream just before serving, as it will melt quickly. For fewer than 4 servings, cut the recipe in half or a quarter, and blend each serving when ready.