1. Wash the apple and don't have to peel and grate into very thin slices. Banana cut into small cubes
2. Beat the butter until it is soft. Add sugar by two times, mix until it looks creamy.
3. Beat the egg and add into the butter. Add half first and mix until they are incorporated and add the rest and mix.
4. Add milk / water and mix.
5. Add apple slices and stir.
6. Mix cake flour and baking powder and sift. Add half of the flour into the mixture and mix gently and continue until everything is combined. Add half of the banana cubes and stir.
8. Use a spoon to put the muffin into the muffin paper mold, add the rest of the banana cubes to the top of the muffin.
9. Put it into the preheated 175 degree oven for 30 minutes.
