First, break the egg into a bowl and beat until foamy. This helps incorporate air, making the cake lighter and fluffier. Then, add the mashed bananas. The riper the bananas, the sweeter and more flavorful your cake will be.

Next, incorporate the cooked tapioca, cornmeal, and baking powder. These ingredients provide structure and texture to your cake, ensuring it holds together well without flour or sugar. Mix everything together thoroughly.

Gradually add the milk or water to the mixture. The amount of liquid may vary slightly depending on the moisture content of your bananas and tapioca, so add just enough to achieve a uniform, smooth batter. The batter should be pourable but not too runny.

Pour the batter into a greased center-hole pan. Greasing the pan with margarine or any other preferred fat prevents the cake from sticking, making it easier to unmold later. Cover the pan with aluminum foil or a lid to retain heat and moisture during cooking.

Place the pan directly on the stove over medium heat. Cook the cake for 30 minutes, ensuring the heat is evenly distributed to avoid burning. After 30 minutes, carefully unmold the cake.

Return the unmolded cake to the pan and place it back on the stove for another 10 minutes. This step helps achieve a firmer texture and a slightly crisp exterior. Once done, your flourless and sugarless stovetop cake is ready to be enjoyed!