Preheat oven to 350°F. Line cupcake pan with liners or spray a 13x9 inch pan with cooking spray.

Beat together the butter, pineapple juice, rum, and vanilla. Add the eggs, one at a time, mixing until well blended.

In a separate bowl, mix together the flour, sugar, baking soda, baking powder, and salt.

With a mixer on low speed, gradually add the dry ingredients to the wet. Fold in the pineapple and coconut.

Fill cupcake liners 3/4 of the way full, or pour all of the batter into the greased 13x9 inch pan. Bake for 20-25 minutes until a toothpick comes out clean.

While still warm, top the cooked cupcakes with the Malibu syrup. When cool, frost with the lime-cream cheese frosting.

To make the Malibu Syrup: bring sugar and water to a boil. After 2 minutes, add Malibu, vanilla, and butter. Let cool 3-5 minutes until syrupy.

To make the Lime-Cream Cheese Frosting: combine all ingredients except powdered sugar using a hand mixer. Add the powdered sugar gradually to desired sweetness and consistency.