Peel the apples from the skin and cut them into cubes.
Put the prunes in a saucepan, add 75 g of brown sugar and 150 ml of water. Place on the heat for 15 minutes. Then pour out the water, put the prunes in a bowl, add the amaretto, mix all together, cover it with a lid, and leave it overnight.
Make the streusel. Add 25 g of butter to 75 g of flour, then add the demerara sugar, drizzle it with a spoonful of cold water, and mix it.
Prepare the base of the cake. Sift 75 g of flour and baking powder into a bowl, add 50 g of butter, 25 g of almonds, egg, milk, 50 g of brown sugar and knead the dough. Add the apples and place the dough in a mold greased with some butter.
Put the prunes, streusel, and 50 g of almonds on the top.
Bake the cake for 1 hour at 180 degrees. Take it out of the oven, leave it for 30 minutes, and flip the cake over onto a rack. Before serving, sprinkle the cake with powdered sugar.