Beat the butter, eggs and sugar until frothy. Then add flour, baking powder and milk and stir well. Pour the mixture into 12 muffin cups. For each muffin, cut a children`s bar into narrow strips and distribute on top of the muffin. Slightly press in a few pieces. So everyone has the same number of chocolate chips and they don`t all sink to the bottom.
Bake the muffins at 200 degrees top / bottom heat for about 25 minutes.