Preheat oven to 350°F. Butter and flour a Bundt pan and set aside.

In the bowl of your mixer, beat cake mix, pudding mix, pineapple (with juice), coconut, vegetable oil, sour cream, and eggs on low speed for one minute. Scrape the sides of the bowl with a rubber spatula, then beat on medium speed for 3 minutes. Pour batter into prepared Bundt pan and spread evenly. Bake for 40-50 minutes or until a toothpick inserted in the center does not come out with raw batter.

Let cake cool in pan for 10 minutes before inverting onto wire rack to continue cooling. While cake cools, prepare glaze.

In a small bowl, whisk together warm water, cream of coconut, and rum extract. Add powdered sugar and whisk until smooth. Spoon evenly over the cake, spreading as needed. Let the glaze soak into the cake as it continues cooling.

To make the frosting, in the bowl of your mixer, beat butter and powdered sugar until smooth and combined. Add pineapple juice and beat on medium low until combined. Increase speed to high and beat for one minute. Frost cooled cake. Top with additional coconut, if desired. Refrigerate until ready to serve.