Preheat your oven to 325°F (165°C). Spread 1 cup (100g) of the sweetened shredded coconut in an even layer on a baking sheet. Bake for 5 to 7 minutes, stirring every 2 minutes. Watch carefully and remove it from the oven the moment you see a beautiful golden-brown color. Let it cool completely.

Increase the oven temperature to 350°F (175°C). Grease three 8-inch (20cm) round cake pans and line the bottoms with parchment paper. In a medium bowl, whisk together the cake flour, baking powder, and salt. In the bowl of your stand mixer, beat the softened butter and granulated sugar on medium-high speed for 3-4 minutes until pale and fluffy. Add the egg whites one at a time, beating well after each addition. Pour in the vanilla and coconut extracts.

Turn the mixer to low speed. Add a third of the dry flour mixture to the butter mixture, followed by half of the coconut milk. Repeat this process, ending with the final third of the dry ingredients. Mix only until you no longer see dry streaks of flour.

Divide the batter evenly among the three prepared cake pans, smoothing the tops with an offset spatula. Bake for 22-25 minutes. You will know they are done when the edges pull away slightly from the pan and a toothpick inserted into the center comes out clean. Allow the cakes to cool in their pans for 10 minutes before inverting them onto wire racks to cool completely.

In a clean mixer bowl, beat the softened butter for 2 minutes until creamy and smooth. Gradually add the powdered sugar, one cup at a time, beating on low speed. Add the thick coconut cream, coconut extract, and a pinch of salt. Increase the speed to medium-high and whip for 3-4 minutes until the frosting is thick, bright white, and incredibly fluffy.

Place the first sponge layer on a serving plate. Spread a thick layer of frosting over the top. Repeat with the second and third layers. Use the remaining frosting to completely cover the outside and top of the cake. Press the remaining untasted white shredded coconut densely into the sides of the cake. Sprinkle the top with a mix of the remaining white coconut and the golden-brown toasted coconut.