Beat sugar, eggs, butter, sour cream and rum extract until combined. Add flour, baking powder, baking soda and salt.
Add pineapple and coconut. Stir.
Add 24 cupcake liners to muffins. Fill about 3/4 way full with muffin batter. Bake for 25 minutes or until a toothpick comes out clean. Cool on a cooling rack.