Preheat oven to 350°F. Line the bottom of two 9-inch pans with parchment paper and spray with non-stick spray.
Add egg whites to a small bowl or stand mixer fitted with a whisk attachment and beat until stiff peaks form. If using a stand mixer, transfer egg whites to a small bowl and set aside.
In a separate small bowl, combine the buttermilk and baking soda and set aside.
Add the sweetened flaked coconut to a food processor and pulse until fine.
Add minced coconut to a medium mixing bowl with the flour.
Mix together the coconut, flour, sugar, and salt to a large bowl or stand mixer.
Add the butter and mix until sandy in texture.
Scrape down the sides and beat in the egg yolks.
Beat in the flour mixture and buttermilk alternately until fully combined, scraping down the sides as needed.
Fold in the coconut extract and egg whites, evenly divide the batter between the two pans and bake for 35 to 40 minutes until toothpick comes clean.
Remove from oven and let cool in the pan for 5 minutes before transferring to a cooling rack to cool completely. See notes for alternative sizes and measurements.
Frosting
Add cream cheese and butter to a large bowl or stand mixer fitted with a paddle attachment and beat on medium-high speed until fluffy. Slowly add in the sugar a cup at a time, alternating with the heavy cream and extract. Beat on high for 2 to 3 minutes until light and fluffy. Add more sugar or cream to reach desired consistency.
Add bottom cake layer to a plate or cake stand and spread some frosting out on the top all the way to the edges. Add the next layer of cake and add more frosting to the top, spreading it evenly and down over the sides.
Gently use the palm of your hand to press shredded coconut onto the sides and top of the cake, pipe on additional decorative frosting around the base of the cake and on top if desired.
Notes
Make a 6-inch 4-layer cake: 2 cups of batter per 6-inch pan, bake for 30-35 minutes. Make 24 cupcakes: 2 to 2.5 tbsp batter per cupcake liner, bake 18-23 minutes. Make a 6-inch 2-layer cake and 12 cupcakes: Follow guidelines above.