Put flour, powdered sugar and salt in a bowl and mix.
Add butter in small pieces and crumble.
Add egg and knead to a dough.
Roll out the dough on a floured surface then place in a springform pan Ø26cm, and form. (up to the rim)
Place in refrigerator.
Peel, core and quarter the apples, then cut into thin slices.
Mix apple slices with cinnamon.
Fill apples in the shortcrust dough.
Bring butter and sugar to melt in a medium pot.
Stir in flour.
Pour in the butter/sugar cream and stir until smooth. Place away from heat.
Mix in the flaked almonds.
Pour the mixture onto the cake and spread it out evenly.
Bake in preheated oven at 180°C for about 60 minutes
Leave to cool.