Preheat oven to 350°F (177°C). Thoroughly grease the interior of a 6 inch round one-piece cake pan (so no springform pan or pan with removable bottom) with cooking oil spray. Line the bottom with a parchment paper round.
Add eggs and condensed milk to a large mixing bowl. Whisk until eggs are fully beaten and incorporated into the condensed milk. Add in the coconut. Whisk until evenly combined. Let the mixture sit for about 10 minutes. This gives the coconut some time to absorb some of the liquid and you will see the mixture thicken.
After ten minutes, whisk the batter briefly one more time just to make sure the batter is evenly thick and coconut is evenly distributed. Pour the batter into the prepared cake pan.
Bake cake for about 35-40 minutes or until done. When cake is done, the surface will be golden brown and may be puffed up and may have a few cracks. A toothpick inserted should come out clean. The surface of the cake should level once the cake is out of the oven (and the cracks will disappear). Let cake cool completely before decorating or serving.
Optional Frosting: After the cake is fully cooled and right before serving, spread a thin layer of the remaining condensed milk across the cake and then sprinkled more shredded coconut on top. I recommend you do this right before serving because otherwise some of the condensed milk will soak into the cake if you add it too early.
Notes
You must use a solid one-piece cake pan because the batter will leak through if you use a springform cake pan. You can use a square cake pan instead of a round pan but your cake may be thinner depending on the size of your square cake pan (most ones in the US are 8 x 8 inch which would result in a much thinner cake).
The cake is very sweet and rich so I recommend smaller slices.
If you are using a 14 oz can of condensed milk, you will not use the full amount. You should have about 1/4 cup leftover which you can use to decorate the cake or use for another recipe.
Make sure to use unsweetened shredded coconut. Make sure it is shredded and not flakes. And make sure it is unsweetened because otherwise the cake will be too sweet. I used Let's Do Organic Unsweetened Shredded Coconut.
I have only made this cake successfully with sweetened full fat condensed milk. I did try it with coconut condensed milk but the cake did not bind well and fell apart once sliced. It may be possible to get it to work with coconut condensed milk but you likely would need to alter the other ingredient quantities.
The flowers in the photos were for decoration only. They were not consumed.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.