Heat an air fryer to 400°F. Meanwhile, if needed, peel 1 small butternut squash, halve and remove the seeds, and cut the flesh into 1/2-inch cubes (about 5 cups). Transfer the squash to a large bowl.
Add 1 1/2 tablespoons olive oil, 1 teaspoon kosher salt, 1/2 teaspoon garlic powder, and 1/4 teaspoon black pepper to the squash. If making the savory variation, also add 2 teaspoons ground cumin and 1 teaspoon paprika. If making the sweet variation, also add 2 tablespoons maple syrup and 2 teaspoons ground cinnamon. Toss to coat.
Working in batches, add the butternut squash to the air fryer basket in a single layer. Air fry until the butternut squash is tender with browned and crispy edges, shaking the basket or tossing halfway through, 12 to 16 minutes total.
Transfer to a bowl and loosely tent with aluminum foil to keep warm while you air fry the remaining squash.