Peel the orange, then remove the membrane and the pips. Put the flesh into a blender. Add the flour, milk, egg and baking powder. Whiz, until you get a thick batter. Set aside.
Peel the pineapple, then core and cut it into 1cm thick rings.
Heat a lightly oiled griddle pan and fry the pineapple rings until lightly charred and caramelised. Let them cool, then set aside about 3 rings, and finely chop the rest.
Mix the chopped pineapple pieces with the batter, adding any jus.
Heat a lightly oiled pancake pan, then add dollops of the batter, letting them spread out into circles (or use silicon pancake moulds).
Cook for a minute or so. When the surface is no longer wet, flip them over and cook for another minute or so, until the other side is golden too.
Transfer them to a plate and repeat with the remaining batter.
Meanwhile, cut the remaining caramelized pineapple rings into small pieces.
Serve the pancakes with the pineapple pieces and maple syrup or honey.