**Prepare Apples:** Wash and dry the apples. Slice them into 1/4-inch thick rounds and remove the cores with an apple corer or a small round cutter to create rings.
**Make the Batter:** In a mixing bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt. In another bowl, combine the milk, egg, and vanilla extract. Gradually add the wet ingredients to the dry ingredients, whisking until smooth.
**Heat Oil:** Heat about 1 inch of vegetable oil in a frying pan over medium heat until it reaches 350°F (175°C).
**Dip and Fry:** Dip each apple ring into the batter, ensuring it’s fully coated. Carefully place the battered rings into the hot oil, frying 2-3 at a time. Cook for 1-2 minutes per side, or until golden brown.
**Drain:** Remove the fried apple rings with tongs or a slotted spoon and place them on a paper towel-lined plate to drain excess oil.
**Coat with Cinnamon Sugar:** While still warm, sprinkle the apple rings generously with cinnamon sugar.
**Serve:** Serve warm and enjoy with caramel sauce, whipped cream, or a dusting of powdered sugar if desired.