Preheat your oven to 220°C/Fan 200°C/Gas 7. Slice your squash in half so you have two mirror image pieces. Set on a baking sheet, cut-side down. Roast for 30 mins or till a knife goes into the squash as if it were butter.
Remove the squash from the oven. Leave to cool, then chop into chunks (no need to peel) and add to a blender. The longer it cools, the better. But if you can’t wait long, carefully chop into chunks and add to a blender with ice to cool it down.
Peel, core and cube the apples (see tip below). Add the dates, cubed apples and 2 tsp of the ground cinnamon to a high speed blender or food processor. Blitz till smooth, trickling in 250ml-350ml cold water as you blend to get the consistency you want. Taste. Add more cinnamon if you like. Serve cold. Whizz in ice if needed.