For the pancakes, place all of the pancake ingredients, except for the knob of butter, into a food processor and blend to make a smooth batter.
Melt the small knob of butter in a crêpe pan over a medium to high heat and spoon a quarter of the batter mixture onto the hot pan, swirling around to cover the pan base. Cook for 30 seconds on each side, or until golden and cooked.
Transfer to a plate and fold in half and then in half again.
For the sauce, heat the ingredients in a small frying pan until the liquid has reduced and thickened.
Pour over the pancakes to serve.