For the cr?pe batter
For the sauce
To make the crêpe batter, put all the ingredients except the oil in a blender or food processor. Add 150ml/5fl oz cold water, and blend to a smooth batter. Alternatively, sift the flour and salt into a bowl, add the eggs and about half of the milk. Whisk to a thick paste. Whisk in the remaining milk and 150ml/5fl oz water for a smooth pouring batter, then add the melted butter. Cover and set aside for 30 minutes.
Heat 1⁄2 teaspoon of the oil in a non-stick 18 cm/7in frying pan. Pour in 4 tablespoons batter and swirl around. Cook for 15 seconds until the edges brown. Turn the pancake over and cook until lightly browned.
Repeat with the rest of the batter to make about 14 pancakes, adding more oil as necessary. Stack them between sheets of greaseproof paper on a plate as you cook them. Rest the plate over a saucepan of simmering water to keep warm.
To make the sauce, put the butter, sugar, zests and juice in a frying pan, and warm gently until the butter has melted. Add the pancakes and warm through gently, turning once.
Pour in the Cointreau and brandy, and swirl carefully over the heat to warm through gently. Once the alcohol is warm, flame the pancakes with a lighted match. Serve immediately.