Preheat the oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds. Brush the insides with olive oil, sprinkle with salt and pepper, and place cut-side down on a baking sheet. Roast for 30-40 minutes until tender.

Heat a large skillet over medium heat and add the spicy Italian sausage. Cook until browned and fully cooked, about 5-7 minutes.

Add the chopped broccoli to the skillet and cook for an additional 5 minutes until tender.

Shred the flesh out of the roasted spaghetti squash with a fork and add it to the skillet with sausage and broccoli. Sprinkle in garlic powder, seasoning with salt and pepper. Mix well.

Remove skillet from heat and stir in half of the cheddar cheese until melted.

Spoon the mixture back into the roasted squash halves, topping with remaining cheddar cheese.

Return the stuffed squash to the oven and bake for an additional 10 minutes until the cheese is bubbly and golden brown.