For the banana croissants, mash bananas and mix well with softened butter, egg yolks, powdered sugar and vanilla sugar. Mix well flour with baking powder, salt, cocoa and cinnamon, add and mix with dough hook to form a dough.
Knead into dough on a smooth surface, then let rest in a cool place. Form thin rolls from the dough, cut off small pieces and shape into croissants.
Press them with the top side into grated almonds. Bake at 190°C until light brown. Roll the banana croissants in sugar with vanilla sugar.