01 - Whisk together flour, cornstarch, sugar, cinnamon, and salt in a medium bowl. Gradually add cold sparkling water, whisking until a smooth, thick batter forms.
02 - Pat pineapple rings dry with paper towels to ensure batter adheres properly.
03 - Pour about 1/2 inch of vegetable oil into a large skillet. Heat over medium-high heat until the oil shimmers and is ready for frying.
04 - Dip each pineapple ring into the batter, allowing excess batter to drip off for even coating.
05 - Fry pineapple rings in batches for 1–2 minutes per side until golden and crisp. Do not overcrowd the pan to maintain proper oil temperature.
06 - Transfer fried pineapple to a plate lined with paper towels to drain excess oil. Serve warm, drizzled with honey or maple syrup, and topped with toasted coconut or vanilla ice cream if desired.