Peel and cut squash into small similar-sized chunks so they cook evenly. Toss the squash with oil, garlic powder, salt and pepper. Place on a foil-lined baking sheet and cook until soft, about 15-20 minutes.
In a saucepan, melt the butter. Once the butter is melted, stir in the cream to warm and then remove from the heat and set aside.
Whip the squash to break it up. Slowly add in the cream and butter mixture while whipping until it is mostly smooth. Stir in the sage and season with salt and pepper to taste.