Combine eggs and sugar, beat lightly. We will bake the cake in a cup in which the dough is kneaded.
Add soft butter and yogurt, beat lightly with a whisk - just until all the ingredients are combined.
Add flour sifted with baking powder and vanilla, mix quickly until smooth. Do not knead for a long time, otherwise the dough will be rubbery.
Peel the apple from the core and cut into thin slices.
Arrange the apples in a fan on the surface of the dough, sprinkle with ground cinnamon. Fill the mug with dough should be no more than 1/3 of the height of the cup.
Bake at maximum power for about 2 minutes, the approximate time depends on the power of the microwave. The cake will rise during baking, then settle a little, the main thing is not to dry it out, pull it out slightly moist.