Preheat oven to 350 degrees F. Spray 2 (9-inch) round cake pans with non-stick spray and line the bottom of each with parchment paper.
Place coconut milk and butter in a small saucepan and heat over low heat.
Place yolks, eggs, and sugar in a large bowl and place over a pot of simmering water. Whip until tripled in volume.
Sift together the flour, baking powder and salt. Fold the flour mixture into the eggs in 3 installments and then gently fold in the milk mixture. Fold in the coconut and divide the mixture evenly between the 2 pans.
Bake for 20 to 25 minutes or until the center of the cake springs back when gently pushed. Cool on a baking rack then gently remove from the pan. Slice the cakes in 1/2, horizontally, and soak each 1/2, with 1/4 cup of the Rum Simple Syrup.
Spread 1/2 cup of the Ganache Filling onto each of the 4 layers of cake and stack the layers. Spread the remaining Ganache Filling over the top and side of the cake.
Place the Coconut Spray mixture in a paint sprayer and spray the entire cake with the mixture.
Serve Macerated Berries alongside the slices of cake.
Rum Simple Syrup:
Combine rum and sugar in a small saucepan set over medium-high heat. Cook until the sugar is dissolved. Let cool.
Place white chocolate in a large bowl. Bring coconut milk and heavy cream to a simmer. Pour the warm milk over the chocolate and let sit 1 minute, then whisk until smooth and fold in the coconut.
Place rum in a small bowl. Add the gelatin and let dissolve completely. Whip the cream to soft peaks, add the gelatin, and continue whipping just until stiff peaks form. Fold the whipped cream into the ganache.
Melt the chocolate and cocoa butter in a medium bowl set over a pot of simmering water.
Mixed berries 1 cup blackberries 1 cup strawberries, halved 1 cup raspberries 3/4 cups sugar 1/4 cup raspberry or black currant liqueur 2 teaspoons vanilla extract
Place the berries in a medium bowl. Add the sugar, liqueur, and vanilla, cover the bowl with plastic wrap and let sit at room temperature for 1 hour.