Peel the apples, remove the seeds, and then slice them thinly using a mandoline.
Add the eggs and sugar to a large bowl, and beat the ingredients with an electric mixer until you get a tall, whitish mixture.
Add the vegetable oil and grated lemon zest, and mix again.
Add the sifted flour and baking powder, and continue mixing with the electric mixer until you get a lump-free mixture.
Finally, add the milk in 2 batches, mixing after each addition.
Add the sliced apples and gently mix with a spatula.
Pour and level the mixture into a 20cm cake tin lined with parchment paper.
Bake at 180°C for about 40 minutes.
