Dice the apple into small cubes and roughly chop the walnuts and almonds.
Mix oatmeal, whole wheat flour, baking powder, and salt in a bowl.
In another bowl, combine the egg, milk, olive oil, and apple cider vinegar.
Combine the wet and dry ingredients to make the dough.
Add the diced apple, walnuts, and almonds and mix evenly.
Pour the batter into an oiled pan or loaf mold.
Bake in a preheated oven at 180°C (356°F) for 30-35 minutes.