In a large bowl, whisk together flour, sugar, baking powder, salt, and cinnamon.
In a separate small bowl, whisk the milk, egg, and vanilla together.
Pour the wet ingredients into the dry and stir until just combined.
Fold in the chopped apples. Don’t overmix.
Heat oil in a deep skillet or pot to 350°F (175°C). Use a small scoop or spoon to drop batter into the oil.
Fry in batches for about 2–3 minutes per side until golden brown and cooked through.
Remove with a slotted spoon and drain on a paper towel-lined plate.
Dust with powdered sugar or drizzle with glaze while still warm.