yield: 8 to 10 servings prep time: 1 hour 30 minutes/cook time: 35 to 45 /minutes total time: 2 hours 30 minutes
For the Cake:
2¼ cups cake flour
1¼ cups granulated sugar
2 teaspoons baking powder
½ teaspoon kosher salt
¾ cup unsalted butter, at room temperature, cut into 2-inch pieces
6 egg whites
1 cup coconut milk
1 cup sweetened shredded coconut
1 vanilla bean, split in half lengthwise
For the Frosting:
1½ cups granulated sugar
6 egg whites
1½ cups unsalted butter, at room temperature, cut into 2-inch pieces
1 teaspoon vanilla extract
¼ teaspoon kosher salt
⅔ cup coconut milk
For the Garnish:
1 cup sweetened shredded coconut
1. Make the Cake: Preheat oven to 350 degrees F. Grease and flour two 8-inch round cake pans; set aside.
2. Sift the cake flour into the bowl of an electric mixer. Add the sugar, baking powder and salt and beat on low speed for 15 seconds to combine. Add the butter pieces and beat on low speed for 1 minute, or until the mixture is coarse and crumbly.
3. In a separate medium bowl, whisk together the egg whites, coconut milk and the 1 cup shredded coconut until combined. Scrape the seeds from the vanilla bean into the mixture and whisk to thoroughly incorporate the seeds throughout the mixture.
4. Add half of the coconut milk mixture to the dry ingredients and beat on medium-high for 1 minute. Scrape down the sides and bottom of the bowl, add the remainder of the coconut milk mixture and beat on medium speed for 30 seconds, or until the batter is well-mixed, light and fluffy.
5. Divide the batter evenly between the cake pans and bake for 35 to 45 minutes, or until the tops are firm and golden brown and spring back when pressed lightly in the center. Let the cakes cool completely in the pans on a wire rack.
6. Make the Frosting: In a small, heatproof bowl, whisk together the sugar and egg whites. Place the bowl on top of a saucepan with about an inch of simmering water (do not let the bottom of the bowl touch the water). Heat the mixture, whisking occasionally, for 6 to 8 minutes, or until the mixture is hot to the touch and the sugar is dissolved.
7. Remove the bowl from the heat and transfer the mixture into the bowl of an electric mixer. Using the whisk attachment, whip on medium-high speed for 6 to 8 minutes, or until the mixture becomes a light, white meringue and the mixture is cool to the touch. Reduce the speed to low and add the butter a couple of pieces at a time. Increase the speed to medium and mix for 4 to 5 minutes, or until the butter is thoroughly incorporated and the frosting is smooth and glossy. The frosting may initially look curdled after adding the butter, but continue beating and it will come together, looking smooth and creamy by the end of the mixing time.
8. Add the vanilla extract, salt and coconut milk and whip for another few minutes on medium speed, or until the coconut milk is thoroughly incorporated and the frosting is smooth. Again, the buttercream may look thin and separated, but continue mixing until it comes together. It will be more of a satin-like consistency, versus the thick powdered sugar frostings that are often used.
Note: Use the frosting within 30 minutes, or transfer to an airtight container and store at room temperature for up to 1 day, then beat with a mixer (using the paddle attachment) until smooth before using. You can also store the frosting in an airtight container in the refrigerator for up to 2 weeks, then bring to room temperature and beat with a mixer (using the paddle attachment) for 6 to 8 minutes until smooth before using.
9. Assemble the Cake: Remove the cooled cakes from their pans and level the tops, if necessary. Place one cake layer on a cake stand and top with 2 cups of the frosting, using an offset spatula to spread it evenly to the edges.
10. Place the second layer on top, top-side down. Spoon 1 cup of the frosting onto the top of the cake and use a large offset spatula to spread the frosting on top and over the sides of the cake, covering it with a very thin layer (this is the crumb coat). Refrigerate for 20 minutes.
11. Use a wooden spoon to mix the remaining frosting to lighten it up since it has been sitting. Spoon it onto the cake and spread it evenly over the top and down the sides. Use an offset spatula to create a smooth finish. Press the 1 cup shredded coconut onto the top and sides of the frosted cake. The cake can be stored in an airtight container at room temperature for up to 3 days.