In a large Dutch oven heat butter over medium-high heat. Once hot, add in the diced onion and sauté 3-4 minutes, add in the garlic and sauté for another 1-2 minutes. Mix in the rice, butternut squash, garlic powder, and paprika. Stir to combine.
Reduce heat to medium-low. Add in one cup of the stock, stir to combine. Cover with a lid and let cook for 5-7 minutes. Most of the liquid should have absorbed. Add in the white wine, stir to combine.
Cover and cook for 5-7 minutes. Remove lid, stir, and add in another cup of the stock. Cover and cook for another 5-7 minutes. Continue this process until all of the stock has been used. After about 40-45 minutes the rice should be fully cooked and the squash should be fork tender.
Reduce the heat to low, add in the heavy cream and season with salt and pepper. Stir to combine, add in grated parmesan. Serve topped with more parmesan and fresh sage.