Squeeze the lemon and measure out 6 tbsp. juice. Caramelise the sugar in a small pot until light yellow (do not stir in the sugar) and deglaze with lemon juice and 4 tbsp. water. Bring to the boil, reduce temperature and simmer until the caramel is dissolved. Add butter and stir until you have a smooth mixture
Cut the vanilla pod lengthwise and scrape out the pulp with the back of a knife. Stir milk, flour, vanilla pulp and salt until smooth. Stir in egg and 2 tablespoons of oil
Heat a coated frying pan (28 cm Ø) and spread a thin layer of remaining oil in portions. Pour a little batter into the pan, spread quickly by tossing. Pour the excess dough over the edge of the pan and back into the bowl to form a wafer-thin layer of dough. Fry for 1-2 minutes until the bottom is brown. Fold the crêpe in the pan, first halve and then quarter it. Process the remaining dough in the same way, brushing the pan with a little oil each time before frying. Keep the finished crêpes warm in a preheated oven (electric range: 50 °C/ convection oven: not suitable/ gas: not suitable). Arrange the crêpes, dust with icing sugar and serve with lemon syrup