01 - Preheat oven to 350°F. Line a 12-cup muffin tin with cupcake liners.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well combined.
03 - In a large bowl, beat softened butter and granulated sugar with an electric mixer until light and fluffy, approximately 2-3 minutes.
04 - Beat in eggs one at a time, ensuring full incorporation after each addition. Mix in coconut milk, pineapple juice, rum if using, and vanilla extract until smooth.
05 - Gradually add dry ingredients to wet mixture, mixing just until combined. Gently fold in crushed pineapple and shredded coconut.
06 - Divide batter evenly among prepared cupcake liners, filling each approximately two-thirds full.
07 - Bake for 18-20 minutes until a toothpick inserted into center emerges clean. Allow cupcakes to cool in tin for 5 minutes, then transfer to wire rack to cool completely.
08 - Beat butter until creamy. Gradually incorporate powdered sugar, followed by coconut milk, vanilla, and salt. Continue beating until frosting achieves light, fluffy consistency.
09 - Generously frost cooled cupcakes. Top with toasted coconut, maraschino cherry, and pineapple wedge if desired.