1. Halve the pineapples lengthwise with a sharp long knife. Using a small knife, carefully empty the contents of pineapple and cube the fruit. Transfer pineapple shells to the refrigerator until serving.
2. In a large bowl, combine pineapple cubes, kiwi, mango, strawberries, and blueberries. Add sugar and rum. Mix and refrigerate for at least two hours.
3. Combine egg whites, sugar, and vanilla in a heatproof bowl. Begin to beat using an electric hand mixer. Transfer the bowl over a pot of one to two inches boiling water (to become a double boiler) and continue to beat until meringue is creamy and stiff, eight to 12 minutes. Remove from heat and continue beating for five minutes. Transfer mixture to piping bag fitted with a star tip.
4. Preheat oven to 425 degrees Fahrenheit. Fill pineapple halves with fruit salad mixture, forming a mound of salad almost to re-create the complete round shape of a pineapple. Pipe dense meringue kisses to cover the entire fruit salad and complete the thorny shape of pineapple.
5. Transfer the pineapple to oven to brown the meringue kisses. It takes several seconds to two minutes, so have a look at the dish in the oven and make sure the meringues do not burn. Serve immediately with coconut, berry, or your favorite sorbet.