• Preheat oven to 350 degrees F.
• Grease one 10", 2.5-3" high, springform pan or two 9-by-9-by-2-inch cake pans; line bottoms with parchment paper. Grease parchment. I use and really like Bak-Klene ZT Nonstick Baking Spray for all my baking.
• Whisk together flour, baking powder, and salt in a large bowl. Place shredded coconut in bowl of a food processor or blender and pulse until finely chopped. Stir chopped coconut into flour mixture until combined; set aside.
• Beat together butter and sugar in a bowl of an electric mixer fitted with the paddle attachment until light and fluffy, about 4 minutes, scraping down the side of bowl as needed. Add whole eggs, egg whites, and vanilla; beat until fluffy and combined. With the mixer on low, add flour mixture, alternating with coconut milk, beginning and ending with flour mixture, mixing well after each addition.
• Pour batter into prepared pan or divide batter evenly between the prepared pans; smooth with an offset spatula. Bake, rotating pans halfway through, until cakes are golden brown and a cake tester inserted into center comes out clean, about 45 to 50 minutes.
• Transfer pans to a wire rack to cool 30 minutes. Invert cakes onto rack; peel off parchment paper.
• Reinvert cakes and let them cool completely, top sides up, then wrap individually in plastic wrap.
• If just using the 2 layers, then transfer to freezer for 15 to 20 minutes. If using the Frieling Cake Slicer, cut your cake into the 5-6 layers.
• Place one layer on a cake plate; spread top with 1/2 of the mango filling.
• Top with the next layer and spread 1 1/2 cup of frosting. Repeat these the layers. Place a final layer of cake and, using the offset spatula, spread remaining frosting over entire cake.
• Cake can be kept refrigerated, covered with a cake dome, up to 3 days.

Thick and Tangy Mango Filling

• Add mango to your blender or food processor
• If using clear jel, sprinkle it over the mango and process
• Once mango is pureed, place in a saucepan over low-medium heat.
• If using cornstarch, dissolve in water and whisk into mango once the mango is heated.
• Regardless of whether you used cornstarch or clear jel, continue to whisk your mango until it is thick and to prevent sticking/burning.
• Once thick, add the lime juice and remove from the heat.
• Let cool completely.
• I put mine in the refrigerator overnight, but I can't promise that the mixture with the cornstarch would remain nice and thick if refrigerated overnight.

7-Minute Frosting with Rum and Coconut

• In the heatproof bowl of an electric mixer set over a saucepan of simmering water, combine sugar, corn syrup, 1/4 cup of water and the egg whites.
• Cook over medium heat, stirring frequently until the thermometer registers 160' on an instant-read thermometer...about 2 minutes.
• Attach the bowl to the mixer fitted with the whisk attachment.
• Beat the mixture on high speed until glossy and voluminous (about 5 minutes).
• Beat in the rum and coconut.
• Use immediately.