First of all, peel the apple and cut it small.
Mash (or purée if you like) the apple kiwi mixture if you don't like big chunks of fruits in your cake (you can simply use a folk to do that).
In a bowl, mix the flour, baking powder and salt. Set aside.
In a bowl of a stand mixer whisk the eggs and sugar until fluffy (you can use a wooden spoon if you don't have a stand mixer).
Add the mashed or puréed fruits (apple kiwi) and whisk for 2 to 3 minutes.
Add the oil slowly while constantly whisking, then add the milk and whisk more.
Pour in the flour mixture and mix well with a wooden spoon until just combined.
Enjoy.