Peel the butternut squash with a sharp vegetable peeler. Cut off the top and bottom, then slice in half lengthwise. Scoop out the seeds with a spoon and discard. Cut into 1-inch cubes, keeping them as uniform as possible so they cook evenly.

In a large bowl, toss the cubed squash with olive oil, maple syrup, garlic powder, smoked paprika, kosher salt, and black pepper. Stir until every piece is coated. The maple syrup helps the edges caramelize and adds a subtle sweetness that balances the smoky paprika.

Preheat your air fryer to 400°F for 3 minutes. Working in batches if needed, arrange the squash in a single layer in the air fryer basket. Do not overcrowd - the pieces should not touch. Air fry at 400°F for 14-18 minutes, shaking the basket once halfway through, until the edges are deeply caramelized and a knife slides in easily.

Transfer to a serving bowl and immediately sprinkle with chopped parsley and flaky sea salt. Serve hot or at room temperature.