Put the flour, cocoa powder, egg and milk into a food processor and blend to a smooth batter. Pour the batter into a jug and heat the oil in a 23 cm (9 inch) nonstick pan. Add 100 ml (3½ fl oz) batter to the pan, swirling it around to completely cover the base.
Cook the pancake for 1–2 minutes until pale golden on the underside, then turn it over and fry the other side. Tip on to a plate and repeat 3 more times with the batter to make 4 pancakes, interleaving them with nonstick baking paper as they pile up on the plate.
Put a few pieces of chocolate honeycomb bar into the centre of each pancake and fold in all 4 sides to make a rectangle.
Heat the butter and sugar in the frying pan and when the sugar has dissolved, add the orange rind and juice and slip in the pancakes. Warm through for 3 minutes. Serve the pancakes drenched in the orange sauce.