Start by chopping the bananas into round slices and transfer them to a saucepan, cover them with water and add the salt, cover the pan and cook for 10 minutes over high heat.
After this time, turn off the heat and drain the water.
Transfer them to a bowl, add the butter, mash very well. Add the cheese and mix it all together very well by hand.
After that, add the egg and the wheat flour, mix well again.
Split this mixture into 4-equal sized portions and round them into balls.
Transfer one of these balls to a flat surface covered with a plastic bag or plastic wrap, then cover the ball with another plastic bag.
Flatten this ball by hand into a pancake shape. Repeat this process with all the balls.
Into a skillet, add a pancake and cook each side for 5 minutes.
Do it to every pancake.
Cut the pancakes horizontally, halfway through, and stuff them with some grated mozzarella cheese, transfer them to a skillet over low heat and cook for 1 minute, or until the cheese melts.
Serve.