Stir butter, sugar and spices until smooth. Add the oil and the flour sifted with the baking powder and knead into dough. Refrigerate. (Tip: make the dough one day ahead.) Peel, core and dice the apples and mix well with the remaining ingredients.Remove the dough from the refrigerator, knead quickly and roll out to about 8mm (1/3 in.). Cut out a 26cm circle and place in the bottom of a 26cm springform pan. Top with the apple filling and press down lightly. Rub the rest of the cold dough into streusel on top with a grater or through a sieve.
Baking time: about 70 minutes
Baking temperature: Preheat the conventional oven to 210°C (400°F) reduce to 180°C (350°F) once the cake is in the oven.