Preheat oven to 350°F (175°C). Grease a 9x13 inch baking pan.
In a large bowl, whisk together sweetened condensed milk, coconut milk, evaporated milk, and melted butter until smooth.
Add lightly beaten eggs and vanilla extract. Mix well.
Stir in granulated sugar and salt until sugar is dissolved.
Add grated cassava and mix until evenly distributed.
Pour batter into the prepared pan and spread evenly.
Bake for 50-60 minutes, or until a toothpick inserted into the center comes out with moist crumbs.
While baking, prepare topping: In a small bowl, mix evaporated milk and sweetened condensed milk.
Once cake is baked, pour topping evenly over hot cake.
Optional: Broil for 1-2 minutes for a golden top. Watch carefully.
Cool completely in the pan before slicing and serving.