01 - If using fresh pineapple, peel, core, and slice into 1/2-inch thick rings. Pat the rings completely dry with paper towels to remove excess moisture.
02 - In a medium bowl, whisk together flour, cornstarch, sugar, baking powder, and salt until well combined. Stir in cold sparkling water and egg (if using) until just combined. Do not overmix—small lumps are acceptable.
03 - In a deep skillet or saucepan, heat vegetable oil to 350°F. Use a kitchen thermometer to verify temperature.
04 - Dip each pineapple ring into the batter, ensuring even coating. Allow excess batter to drip off before frying.
05 - Carefully place battered rings in hot oil, working in batches to avoid overcrowding. Fry for 1–2 minutes per side until golden brown and crispy. Remove with a slotted spoon and drain on paper towels.
06 - Dust hot fried pineapple rings generously with powdered sugar. Add a sprinkle of cinnamon if desired. Serve immediately while warm, optionally with vanilla ice cream or caramel sauce.