2 to 3 cups grated fresh or packaged unsweetened coconut
1.
Place a rack in the center of the oven, and set one rack above it if needed for the third pan.
Preheat the oven to 325°F.
Grease three 8″ or 9″ round cake pans with butter, then dust with flour, and shake out the excess flour.
Set the pans aside.
2.
Place the butter and sugar in a large mixing bowl, and with an electric mixer on medium speed, cream until light, 1 minute.
Add the egg yolks, one at a time, and beat each until just combined.
Add the vanilla.
3.
Sift together the flour and baking soda in a medium-size bowl, and add this in thirds to the egg mixture, alternately with the buttermilk.
Blend on medium-low until smooth.
4.
Place the egg whites in a large bowl and beat with an electric mixer on high speed until stiff peaks form, 4 minutes.
Fold the whites into the batter with a rubber spatula until the whites are just combined.
Divide the batter between the 3 pans.
Place the pans in the oven, with 2 pans on the center rack and 1 pan on the rack above.
5.
Bake the cake layers until they are golden brown and just pull away from the pan, 22 to 25 minutes for 9″ pans, and slightly more for 8″ pans.
Let the cakes cool in the pans set on wire racks for 10 minutes.
Then run a knife around the edges, give them a gentle shake to loosen from the pans, and invert them once and then again to cool right side up on the racks for at least 30 minutes before frosting.
6.
While the cake is baking, make the frosting.
7.
To assemble the cake, place 1 layer on a serving plate or platter.
Cover with a large ladle of frosting and spread until smooth.
Sprinkle on ½ cup of coconut.
Add a second cake layer, cover with a ladle of frosting, then sprinkle on ½ cup of coconut.
Place the final layer on top.
Spread the top and sides of the cake generously with the remaining frosting.
Pack 1 cup of coconut onto the sides of the cake using clean hands.
If desired, sprinkle another 1 cup of coconut on the top of the cake.
Decorate the top and sides with pieces of dried coconut, if desired.
Slice and serve.
