In a large bowl, whisk together the flour, granulated sugar, baking powder, cinnamon, nutmeg, and salt.
In a separate bowl, beat the eggs, then whisk in the milk and vanilla.
Pour the wet ingredients into the dry and stir just until combined into a thick, spoonable batter. Do not overmix.
Gently fold in the diced apples.
Line the air fryer basket with parchment paper. Scoop roughly ⅓-cup portions of batter into the basket, spacing them apart, and shape into rounds.
Lightly spray or brush the tops with oil or melted butter.
Air fry at 350°F (175°C) for 8–10 minutes, checking at 6 minutes, until golden and cooked through. Work in batches as needed.
Cool on a wire rack for a few minutes.
Whisk the glaze ingredients together and drizzle over the cooled fritters (or dust with powdered sugar). Serve warm.