Method
Preheat the oven to 400°F and lightly grease a 9x13-inch baking dish with butter or cooking spray.
In a large bowl, combine the cubed butternut squash and apple slices.
In a small bowl, whisk together the melted butter, olive oil, brown sugar, cinnamon, salt, and nutmeg until fully combined.
Pour the butter mixture over the squash and apples, then toss gently until evenly coated.
Spread the mixture in an even layer in the prepared baking dish.
Bake for 30-35 minutes, stirring halfway through, until the squash is tender and the apples are caramelized.
Remove from the oven and let cool for 5 minutes before serving.