In a medium saucepan, combine crushed pineapple, juice, water, sugar, and coconut rum. Bring the mixture to a boil, stirring frequently until the sugar dissolves. Reduce heat to medium low and allow the mixture to maintain a gentle boil for 35-40 minutes, stirring occasionally. When it's finished, the mixture will be thick and amber colored, with the texture of a jam. Remove from heat and set aside.

Preheat the oven to 350 degrees. Line 2 12 cup muffin tins with paper liners and spray with cooking spray.

In a mixing bowl, whisk together the pineapple juice, egg white, and vanilla extract. Set aside.

In the bowl of an electric mixer, beat together the cake flour, sugar, baking powder, and salt on low speed. Add the cubed butter and beat on medium low speed for about 2 minutes. The mixture will be crumbly.

Pour all but about 1/2 cup of the juice mixture into the flour and beat on medium high speed for 2 minutes. Scrape the sides of the bowl, add the remaining liquid then beat for a final minute.

Scoop cupcake batter into the muffin tins, filling about 2/3 of the way. Add one teaspoon of the pineapple filling into each cupcake. Bake in the preheated oven for 20-24 minutes or until toothpick inserted in the center of the cupcake comes out clean (except for maybe a little sticky pineapple filling :) My cupcakes started to get a little too brown on the top, so I covered them with foil for the last 5 minutes of baking.

Remove the cupcakes from the oven and allow to cool for 5 minutes in the tray, then remove and cool completely.

In the bowl of an electric mixer, beat together cream cheese and butter until smooth and creamy. Add the powdered sugar, one cup at a time, beating well after each addition. Beat in the milk and extracts. If the mixture seems too thick to spread, add another Tablespoon of milk. Stir in the shredded coconut. If you have any leftover pineapple filling, you can add that as well.

Spread the frosting over the cooled cupcakes and top with toasted coconut, if desired.