In a bowl, knead the flour, egg yolk, oil, salt and 130 ml of lukewarm water to form a smooth dough (hand mixer). Shape the dough into a ball, wipe off some of the additional oil and leave to rest at normal ambient temperature for about 30 minutes.
Peel the bananas, cut into slices and immediately drizzle with the freshly squeezed lemon juice so that they don`t turn unappetisingly brown.
Then divide the dough into 6 equal portions. On the work surface coated with a little oil, pull apart each individual portion of dough with your hands to form a thin round flatbread with a diameter of about 20 cm and press into shape.
Heat some clarified butter in a large, non-stick pan. Put a flat cake in it. Now place the banana slices of 1/2 banana in the middle of the pancake and fry until golden yellow over a low heat. Fold the dough in from 4 sides towards the middle (as with an envelope). This creates a square package. Carefully turn this packet over with a spatula and fry the other side until crispy and golden over a low heat. Take out of the pan and keep warm. Fill the remaining 5 flat cakes in the same way and fry them one after the other.
Before serving, the pancake packets can be cut into squares with a pizza cutter.
Serve dusted with powdered sugar. Caution - the `inside` is particularly hot!
Of course, this fine dessert tastes great with a scoop of vanilla ice cream.