01 - If using fresh pineapple, peel, core, and slice crosswise into 1/2-inch thick rings. Pat rings thoroughly dry with paper towels to remove excess moisture, which prevents proper batter adhesion.
02 - In a medium mixing bowl, whisk together flour, cornstarch, sugar, baking powder, and salt until well combined. Pour in cold sparkling water and add egg if using. Stir gently until just combined—small lumps are acceptable. Do not overmix as this develops gluten and toughens the coating.
03 - Pour vegetable oil into a deep skillet or heavy-bottomed saucepan to a depth of 2 inches. Heat over medium-high heat until oil reaches 350°F. Use a deep-fry thermometer for accuracy, or test by dropping a small amount of batter—it should sizzle immediately and rise to the surface.
04 - Working with one ring at a time, dip pineapple into batter, turning to coat completely. Lift and allow excess batter to drip off for 3-5 seconds. A thin, even coating produces the crispiest result.
05 - Carefully lower battered rings into hot oil using tongs. Do not overcrowd the pan—fry in batches of 2-3 rings. Cook for 1-2 minutes per side until deep golden brown and crispy. Remove with a slotted spoon and transfer to paper towels to drain excess oil.
06 - Dust warm fried pineapple generously with powdered sugar. Add a light sprinkle of ground cinnamon if desired. Serve immediately while hot and crispy. Accompany with vanilla ice cream or drizzle with warm caramel sauce for an elevated dessert presentation.