Preheat the oven to 200C/400F/Gas 6.
Beat together the five egg yolks with the flour, caster sugar, vanilla essence and orange zest.
Whisk the egg whites in a large bowl until stiff.
Whisk in the caster sugar with the egg whites until peaks are formed by the whisk.
Fold together the white and the yolks and pour into a pudding dish.
Place into the oven for 12-15 minutes, until risen and golden.
Meanwhile, for the coulis, whiz together the raspberries with the icing sugar.
When ready remove the soufflé, place on a plate and drizzle with the raspberry coulis.