Preheat oven to 350F. Grease and flour a bundt pan.
In a large bowl of a standup mixer with a paddle attachment blend butter and sugar together for 2 min. on medium speed until light and fluffy.
Add eggs and coconut extract and blend. Mix flour with the salt and baking powder and add to the mixture along with the sour cream. Beat for 2 min. scraping down the bowl often.
Stir in Blue Curacoa, rum, and pineapple juice. Add blue food coloring to the desired color.
Pour the cake batter into the prepared bundt pan.
Bake for 45-50min. or until a cake tester comes out clean. Cool completely in pan. Invert onto a serving platter.
For the frosting add the sugar, cream of tartar, salt, water, and egg whites in the top of a double boiler or metal bowl. Beat with a handheld electric mixer for 1 minute.
Place pan over boiling water, being sure that boiling water does not touch the bottom of the top pan.
Beat constantly on high speed with an electric mixer for 7 minutes. Beat in coconut extract.
Fold in coconut and ice cake.