Mix the flour, oats, baking powder and salt in a bowl. Whisk together the apple, honey, eggs and milk, pour into the flour, whisk until the batter is smooth.
Heat a little butter in a wide, non-stick frying pan. Reduce the heat, pour as much batter into the pan as it takes to make pancakes of approx. 4 cm in diameter. Once the undersides are cooked and no longer stick to the pan, turn the pancakes over, finish cooking and keep warm. Prepare the remaining pancakes in the same way. Plate up the pancakes, dust with icing sugar.