Preheat the oven to 180°C / Gas Mark 4.
Cut the squash in quarters lengthways, and using a spoon scoop out the seeds and membrane.
Line a baking tray with foil and place the squash in the tray skin-side down.
Sprinkle the Whitworths Light Soft Brown Sugar over the squash and dot the butter over the top.
Place in the pre-heated oven and bake for 30-40 minutes, or until the squash is tender and the skin peels away easily.
In a large saucepan heat the olive oil and sauté the onion and garlic over a medium heat for 3-4 minutes.
Add 800ml of stock to the pan with the flesh from the squash and the caramelised sugar and butter from the tray.
Bring the pan to the boil and reduce to a simmer for 15 minutes. Season with salt and pepper to taste.
Turn the heat off and using a hand blender, blend the soup until smooth and serve. Add enough stock to reach the desired consistency.