Preheat oven to 350°F (177°C). Grease three 8-inch cake pans, line with parchment paper rounds, then grease the parchment paper.

Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.

Using a mixer, beat the butter and sugar together on medium-high speed until smooth and creamy, about 2 minutes. Scrape down the sides of the bowl as needed.

Beat in the egg whites until combined, then add the sour cream, vanilla extract, and coconut extract. Beat until combined.

With the mixer on low speed, slowly add the dry ingredients and coconut milk. Beat on low speed until combined, then add the shredded coconut. Whisk by hand to ensure no lumps.

Pour batter evenly into the cake pans. Bake for 21–24 minutes or until a toothpick inserted comes out clean. Allow to cool in the pans for 1 hour, then remove and cool completely on a rack.

To make the frosting, beat the butter and cream cheese together on medium speed until creamy, about 2 minutes. Add confectioners’ sugar, coconut milk, vanilla extract, coconut extract, and salt while mixing on low. Increase to high speed and beat for 3 minutes.

Slice the tops of the cakes for a flat surface. Place 1 layer on your cake stand and cover the top with 1 heaping cup of frosting. Add the second layer and cover with another cup of frosting. Top with the third layer and spread remaining frosting over the top and sides. Sprinkle coconut on top and apply it to the sides.

Refrigerate cake for at least 20 minutes before slicing.