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 handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter and sugar together on medium-high speed until smooth and creamy, about 2 minutes.

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.

Pour batter evenly into cake pans. Bake for 21–24 minutes or until the cakes are baked through.

Allow cakes to cool in the pans set on a cooling rack for 1 hour, then remove from the pans and place the cakes directly on the rack to continue cooling.

In a large bowl using a handheld or stand mixer fitted with a whisk or paddle attachment, beat the butter and cream cheese together on medium speed until creamy and smooth, about 2 minutes.

Add confectioners’ sugar, coconut milk, vanilla extract, coconut extract, and salt with the mixer running on low. Increase to high speed and beat for 3 minutes.

Using a large serrated knife, slice a thin layer off the tops of the cakes to create a flat surface.

Place 1 cake layer on your cake stand, cake turntable, or serving plate. Evenly cover the top with 1 heaping cup of frosting.

Top with second cake layer and evenly cover the top with another heaping cup of frosting. Top with the third cake layer.

Spread the remaining frosting all over the top and sides. Sprinkle coconut on top of the cake and apply it to the sides.

Refrigerate cake for at least 20 minutes before slicing.