Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easy cleanup.
Wash and dry the acorn squash. If it feels too hard to cut, microwave the whole squash for 1 to 2 minutes to slightly soften the skin.
Cut off the top and bottom of the squash for stability. Slice it in half from stem to tip and scoop out the seeds and stringy center.
Place each squash half cut-side down and slice into 1/2-inch thick half-moon slices.
In a mixing bowl, combine Parmesan cheese, melted butter, fresh herbs, garlic powder, salt, and black pepper until evenly mixed.
Arrange squash slices in a single layer on the baking sheet. Press half of the Parmesan mixture onto one side of each slice, flip, and repeat on the other side.
Roast for about 25 minutes until the squash is fork-tender and the Parmesan edges are crispy and golden brown.
Transfer to a serving plate and garnish with extra Parmesan, parsley, or a drizzle of maple syrup if desired. Serve warm.
Air Fryer Method: Preheat air fryer to 375°F (190°C). Arrange slices in a single layer and air fry for 12 to 15 minutes, flipping halfway through until crispy and tender.
Roasted Seeds Bonus: Rinse and dry the squash seeds. Toss with olive oil and salt, then roast at 325°F (163°C) for 10 minutes until lightly golden.