Chop the bananas into round slices and place them in a bowl.
Add the eggs, transfer all these ingredients to a blender, pour in the milk and blend all the ingredients until combined.
In a skillet over medium-low heat, add the sugar and stir until fully melted.
Gradually add the water and keep stirring until a caramel sauce forms.
Transfer all this caramel sauce to a 20cm diameter ring cake tin and spread it well.
Pour in all the banana batter we made.
Cover the cake tin with aluminum foil and place the cake tin into a large baking pan; add enough water to cover half of the cake tin.
Take to a preheated oven at 180°C (350°F) and bake for 1 hour and 30 minutes.
After this indicated time, remove from the oven and let it cool.
Next, take it to the fridge and let it chill for 1 hour.
Unmold and serve.