Whisk the eggs, egg-yolk and the plain flour together in a mixing bowl.
Add the milk and whisk to form a loose batter.
Season with the crushed lavender leaves.
Melt half the butter in a large non-stick frying pan over a medium heat.
Spoon in enough batter to coat the base of the pan in a thin layer.
Turn the pancake over when the base is golden-brown. When both sides are browned, remover the pancake from the frying pan and transfer to a warm plate.
Repeat until all the batter has been used.
For the filling, mix all the filling ingredients together in a mixing bowl.
Spoon the mixture into the centre of the cooled pancakes and roll up. Serve at once.