Preheat oven to 450°F / 232°C.
In a microwave-safe bowl, whisk together vinegar, 2 Tablespoons olive oil, mustard, maple syrup, and garlic. Heat in the microwave until warm, just about 30 seconds. Stir cranberries into warm dressing. Set aside to soak.
Meanwhile, toss squash with 2 Tablespoons olive oil, sage, and salt. Spread out on a sheet pan and roast, until tender and golden, about 20 minutes. (Note: Remove the pan from the oven and gently slide a spatula under the squash to help prevent sticking, but don't flip it over. Cooking it just on one side will help that side to get extra golden brown and crisp.)
When squash is tender, carefully transfer to a large mixing bowl.
Drizzle dressing (including cranberries) over squash. Top with parsley. Gently fold everything together.
Serve warm or room temperature.