Start by preheating the oven to 180 degrees Celsius.
Grease a 21 cm cake tin or use a baking sheet.
Cut 3 of the apples ( the last apple goes on later) into small pieces and put them in a small saucepan with just enough water to cover them.
Add a pinch of salt, cinnamon, vanilla extract and raisins.
Cook for about 20-25 minutes at very low heat, or otherwise the apples might burn. Checking occasionally.
Once cooked, transfer the apple mixture to a large bowl and mash it with a whisk or masher. You can also use a food processor to mash them.
Then add the whole-wheat spelt flour, baking powder, baking soda, egg, and mix.
Transfer the mix to a cake tin.
Use the last apple to cover the entire cake with apple slices and bake for about 25 minutes, or until the cake tester comes out clean.
Let cool down for 5 minutes before transferring to a cooling rack or plate.
You can sprinkle grated toasted almonds and honey on top of the apples when you take it out of the oven.
Enjoy with honey, plain yoghurt, Greek yoghurt, whipped cream or date syrup.