Grease baking pan with butter or oil. Place banana leaves on top if using and grease the top as well. Pre-heat oven to 180c/ 375f.
Beat the eggs in a large mixing bowl. Add all the cake ingredients EXCEPT for the grated cassava. Mix well until sugar is dissolved. Do a taste test and add more sugar, if preferred.
Add the grated cassava. Stir until combined. Pour into the baking pan.
Place in the middle rack and bake for 45 minutes to 1 hour until a toothpick inserted comes out clean. Check doneness at 43 mins.
Remove cake from the oven. Sprinkle ¼ cup grated cheese on top. This is optional. Pour condensed milk, spreading evenly to the edges. If using the custard topping: place all ingredients in a bowl. Stir until combined then pour on top of the cake. Spread evenly.
Return to the oven on the upper-middle rack and BROIL until the top is golden. Watch carefully and rotate the pan if needed.
Sprinkle remaining cheese on top. Let the cake cool for 2-4 hours or overnight before slicing. Serve and enjoy!
If using fresh cassava root: Cut the root into 2 to 3 pieces. Slice through the peel of each piece vertically then gently wedge a paring knife under the bark so that it lifts up and be easily removed (see video). Wash the flesh thoroughly to remove any dirt and leftover pieces from the bark. Soak for 20 minutes then discard the water. Grate using a food processor or a hand grater. For added texture, shred the cassava using the large holes of the grater.
Grated young coconut can be substituted with macapuno. I recommend draining the syrup to lessen the sweetness.
Storage and shelf life: Leftovers can last in the fridge for 3 to 4 days but I highly recommend consuming it within 3 days for the best flavor and texture.