Using a drill, drill a hole into the top of your coconuts. Drain the juice of each coconut into their own glasses. Set aside for late. (In case a coconut has gone bad your juices are in separate glasses for easy tossing.)
Grate the coconut on a small grate. Set aside. (Once you get down to pieces too small to grate, use a food processor to shred them.)
Preheat oven to 350 degrees. Butter and flour 3 - 9 inch pans or use 2 - 9" pans and use remaining batter for a few cupcakes. You can also use parchment paper in the bottom of the pans to prevent sticking. This is what I do most of the time.
Beat together the butter, sugar, salt and vanilla until light and fluffy.
Add the eggs and mix until combined.
Add half the flour and then the milk. Mix in the last bit of flour just until combined.
Fill each pan half full and place in the oven. Bake for 32-35 minutes or until a tooth pick comes out clean. Rest in the pans for a couple of minutes and then turn out onto a cooling rack.
Prepare the icing by mixing the evaporated milk and powdered sugar in a bowl. Stir until smooth.
Starting with the first layer sprinkle a small amount of reserved coconut juice onto the cake. Add a generous amount of icing to the top and then cover in grated coconut. Add the second cake layer and repeat.
Lastly, spread the icing around the sides of the cake and cover in grated coconut.