Preheat the oven to 400 degrees Fahrenheit and line a 12x16 inch baking pan with parchment paper and set aside.
Mix the olive oil, basil, garlic powder, oregano, rosemary, chili flakes and salt together in a small bowl.
Add the potatoes to a large bowl and pour half of the olive oil mix over top and stir to combine.
Add the potatoes to the prepared baking pan and spread them out in an even layer.
Bake the potatoes for 15 minutes.
Add the squash to the bowl and pour the remaining olive oil blend on top and toss to combine.
Once ready, add the squash to the pan and mix it in with the potatoes then add the sausage to the pan.
Drizzle a bit of olive oil on top of the sausages then bake for 20-25 more minutes or until the sausages have cooked through. Flip the sausages over and toss the veggies around half-way through to ensure even baking.
Serve with freshly chopped parsley for garnish if desired.