Peel, quarter, core and slice apples. Immediately drizzle with lemon juice.
Mix all other ingredients together except for the walnuts in a bowl. Mix in the apple slices. Pour into a buttered sprinform (26 cm) dusted with flour. Sprinkle with pieces of walnut.
Bake in a preheated oven at 160 ° C hot air or 180 ° C top / bottom heat for 55-60 minutes until the cake is golden and baked through.
It tastes best when it is lukewarm and dusted with powdered sugar.