Heat the oven to 350°F. Grease two 8-inch round cake pans and line the bottoms with parchment paper. Lightly flour the sides, then tap out the extra flour.

Warm the coconut milk gently until it is just lukewarm. Scrape the seeds from the vanilla bean and stir them into the coconut milk. Set it aside while you prepare the batter.

Beat the softened butter and granulated sugar for about 3–4 minutes, until pale and creamy. Scrape the bowl once or twice as you mix so none of the butter stays around the edges.

Add the egg whites gradually, mixing after each addition. Pour in the vanilla coconut milk mixture and mix until blended. The mixture may look a little uneven at this point, and that is okay.

Whisk the cake flour, baking powder, and kosher salt in a separate bowl. Add the dry ingredients in two portions, mixing on low speed just until the batter comes together. Fold in the shredded coconut using a rubber spatula. Once the flour disappears, stop mixing.

Divide the batter between the prepared pans and smooth the tops. Bake for 28–33 minutes, or until a wooden skewer inserted near the center comes out clean or has a few moist crumbs. Let the cakes sit in the pans on a rack for about 10 minutes.

Beat the softened butter until creamy. Add the confectioners’ sugar gradually, starting on low speed. Add the softened cream cheese, coconut milk, coconut extract, salt, and vanilla. Beat until the frosting is creamy and easy to spread. Fold in the shredded coconut at the end.

Remove the cakes from the pans and let them cool completely. If the tops are uneven, level them gently using a serrated knife. Place one cake layer on a serving plate and spread buttercream over the top. Add the second layer, then cover the top and sides with the remaining frosting. Press shredded coconut gently onto the frosting to finish.