Squeeze excess moisture from the grated cassava using a cheesecloth or kitchen cloth. It should be as dry as possible. Set aside.
Mash the overly ripe bananas with a potato masher, spoon, food processor, or blender until pureed.
In a medium bowl, mix the cassava, salt, and mashed bananas well. The mixture should be firm enough to roll into balls.
Roll about a tablespoon of mixture in the palm of your hands into little bite-sized balls.
Heat oil (about 3 inches deep) to 375℉ (190℃) in a skillet or saucepan. You can also test the oil's temperature by dropping in a 1-inch cube of bread. If it takes 60 seconds to brown, the oil is at 365. Gently place cassava balls in hot oil and fry until golden brown.
Remove from hot oil, drain well, and serve.
Notes
Frozen grated cassava is available in most Asian and Filipino markets, and even some Hispanic markets. If you can't find them grated, you can get the frozen or fresh cassava and blend finely in a food processor or blender.
Please remember that the nutritional information is a rough estimate and can vary significantly based on the products used in the recipe.