Mix the flour and backing powder in a mixing bowl. Add all the other ingredients and mix it with a mixer , first at low speed then till the highest speed till it has crumble consistency. Add 2/3 of the mixture to the springform pan and press it till itcomes to a height about 3cm.
Peel the apples and cut it into wedges (see pics). Mix it with other ingredients and add it to the springform. Then add the rest of the crumble mixture on top of it. Now place it in oven.
slot: lower third
Before serving, sprinkle some icing sugar on top.
Serve with whipped cream.