01 - Pat the pineapple rings dry with paper towels to remove excess moisture. Set aside on a clean surface.
02 - In a mixing bowl, whisk together flour, cornstarch, sugar, baking powder, and salt until evenly combined.
03 - Add chilled sparkling water, coconut milk, and vanilla extract to the dry ingredients. Whisk until smooth and thick, with no lumps remaining.
04 - Pour vegetable oil into a deep saucepan or fryer and heat to 350°F. Use a kitchen thermometer to ensure proper temperature.
05 - Dip each pineapple ring into the batter, turning to coat completely. Allow excess batter to drip off for even frying.
06 - Carefully lower 2-3 battered rings into the hot oil. Fry for 2-3 minutes per side until golden brown and crispy.
07 - Remove fritters using a slotted spoon and transfer to paper towels to drain excess oil.
08 - Dust fritters generously with powdered sugar. Sprinkle with toasted coconut if desired. Serve immediately while warm.