Mix the milk, eggs, salt and sugar with a mixer or whisk. Sieve the flour, add and stir. Cut the bananas into small pieces, puree and mix well with the batter.
Heat the pan well, brush with oil (here`s a tip without a brush: cut a raw potato crosswise, skewer it on a fork, dip it in a bowl with oil and brush the pan with it). Place the batter (a large ladle full for a large pan) in the center of the pan and swivel the pan so that the batter is evenly distributed over the entire surface. As soon as the edges of the pastry are golden brown, turn. About 6 pancakes are baked from the specified amount. Caution: oil the pan before each new pancake!
Let the finished pancakes cool down a little. Then spread Nutella in the middle (you can vary the amount according to your preferences) and fold it up.