Peel, core, and slice the pineapple into half-inch rings. Pat dry to remove moisture so the marinade penetrates better.
Whisk dark rum, brown sugar, cinnamon, and vanilla until smooth. Soak pineapple rings for 10–30 minutes for maximum flavor.
Arrange flour with salt, beaten eggs, and shredded coconut in separate shallow bowls. This keeps coating organized and mess-free.
Dredge rings in flour, dip in eggs, then press into coconut. Ensure even coverage for a crisp, golden crust.
Pour an inch of oil into a skillet and heat to 350°F (175°C). Test with a pinch of coconut; it should sizzle immediately.
Fry 2–3 minutes per side until golden brown. Work in batches and drain on paper towels to keep them crispy.
Whisk mayonnaise, honey, Dijon mustard, and lime juice until smooth. Adjust sweetness or acidity to taste.
Arrange rings on a plate with dipping sauce in a small bowl. Serve hot for the best crunch and flavor.