01 - Peel, core, and slice fresh pineapple into 1/2-inch thick rings. Pat slices thoroughly dry with paper towels to remove excess moisture, which ensures proper batter adhesion and crisping.
02 - In a medium bowl, whisk together all-purpose flour, cornstarch, granulated sugar, baking powder, and salt until well combined. Gradually stir in cold sparkling water and egg (if using) until just combined. Avoid overmixing to maintain a light, airy texture.
03 - Pour vegetable oil into a deep skillet or saucepan to a depth of 2 inches. Heat over medium-high heat until oil reaches 350°F. Use a kitchen thermometer to monitor temperature accuracy.
04 - Dip each pineapple ring into the batter, allowing excess batter to drip off. Ensure an even, thin coating covers the entire ring for uniform frying.
05 - Carefully lower battered rings into hot oil, working in batches to avoid overcrowding. Fry 1–2 minutes per side until golden brown and crispy. Remove with a slotted spoon and transfer to paper towels to drain excess oil.
06 - Dust warm fried pineapple rings generously with powdered sugar. Add a sprinkle of ground cinnamon if desired. Serve immediately while hot, optionally accompanied by vanilla ice cream or warm caramel sauce for enhanced presentation.