01 - Peel, core, and slice fresh pineapple into 1/2-inch thick rings. Pat slices thoroughly dry with paper towels to remove excess moisture, ensuring better batter adhesion.
02 - Whisk together flour, cornstarch, sugar, baking powder, and salt in a medium bowl. Pour in cold sparkling water and add egg if using. Stir gently until just combined—small lumps are acceptable. Avoid overmixing to maintain batter lightness.
03 - Pour vegetable oil into a deep skillet or saucepan to a depth of 2 inches. Heat over medium-high heat until temperature reaches 350°F. Use a kitchen thermometer for accuracy, or test by dropping a small amount of batter—it should sizzle immediately and rise to the surface.
04 - Dip each pineapple ring into the batter, turning to coat completely. Lift and allow excess batter to drip off for a few seconds. A thin, even coating yields the crispiest results.
05 - Carefully lower battered rings into the hot oil, working in batches to avoid overcrowding. Fry for 1–2 minutes per side until golden brown and crisp. 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 crisp, accompanied by vanilla ice cream or warm caramel sauce for an elevated presentation.