1. Using a large bowl, pour both flours, semolina, oats, bran, baking powder and mix thoroughly. In a smaller dish, stir the margarine (or oil) in, then add the sugar and mash to a smooth and fluffy cream. Add to the mixture of bulk ingredients and mix for a while. Form the dough into a ball, wrap in cling film and place in the fridge for half an hour.

2. Prepare a 9 inch springform cake pan, lay some baking paper inside and brush a thin rim of oil, then sprinkle with semolina.

3. Remove the dough from the refrigerator, spread three-quarters of the dough on the bottom of the baking tin and make about 1 1/2 inches high rim. Put the remainder of the dough back in the refrigerator. Pierce the dough on the bottom and on the rim with a fork. Sprinkle with two tablespoons of oats.

4. Peel and seed the apples, cut into thin slices and mix with the juice of half a lemon. If the apples are really sour you can add some sugar, agave nectar or any other preferred sweetener. Lay the apples evenly in the prepared tin. Sprinkle the top with some crumble made from the rest of the dough left in the refrigerator.

5. Put into preheated to 350 F oven and bake for 50 minutes. Remove the baked cake from the oven and leave in the tin until cooled down slightly, then take it out of the tin to cool completely on a cake rack. Once cooled, you can sprinkle the cake with powdered sugar or cinnamon.