How to cook
Cut the butter and mix it with the flour - the goal is to get crumbs. To them, add the remaining ingredients for the butter crust, stir and knead. Make a ball out of it, put it in the fridge for 30 min.
Put one of the sheets in the pie form, cover its walls and bottom. Put half of the walnuts and bananas on top. Smear it with chocolate as well. Distribute the rest of the walnuts and bananas on top.
Use cookie cutters to make several interesting openings on the other sheet. Then use it to cover the pie, by pressing the edges well to the pie form. If you have any excess pie crust left over, cut it off with a knife.
Smear the pie with the egg yolk and bake in a preheated 356°F (180 °C) about 40-45 min.