01 - Combine dark rum and brown sugar in a shallow dish. Add pineapple pieces, turning to coat thoroughly. Allow to soak for 10–15 minutes, flipping halfway through for even absorption.
02 - Whisk together flour, cornstarch, and salt in a medium bowl until well combined. Gradually whisk in cold sparkling water, stirring until a smooth, thick batter forms without lumps.
03 - Pour vegetable oil to a depth of 1 inch in a large skillet or deep pan. Heat over medium-high heat until the temperature reaches 350°F.
04 - Remove pineapple from the rum mixture and pat dry with paper towels to remove excess moisture. Dip each piece into the batter, allowing excess to drip off for an even coating.
05 - Fry pineapple pieces in batches, cooking 2–3 minutes per side until golden brown and crispy. Avoid overcrowding the pan to maintain proper oil temperature.
06 - Transfer fried pineapple to a paper towel-lined plate to drain excess oil. Serve warm, drizzled with honey or maple syrup, sprinkled with cinnamon, and accompanied by vanilla ice cream or whipped cream if desired.