Measure the amount of apples without the core or skin. Grate the apples for the recipe. I used the shredder attachment for my KitchenAid stand mixer on speed one but you can use a regular grater.
Use a whisk or a stand mixer with the beating accessory to mix the butter, sugar, oil, cinnamon, salt and baking powder until you have a homogeneous mix.
Add the egg and milk and mix again.
Incorporate the oats and flour using a spatula or continue using the beating accessory on your stand mixer.
Finish by mixing in the apples.
Take to a preheated oven at 180C / 350F for 15-20min or until you can insert a skewer or sharp knife inside and it comes out without any dough