Preheat the oven to 220C/425F/Gas 7.
Whisk the eggs and flour together in a bowl.
Add the milk, vanilla seeds, double cream and sugar and whisk to make a batter.
Melt the butter in a small ovenproof frying pan and once foaming, add the batter mixture to the pan. Scatter the blueberries over the top and transfer to the oven and bake for 15-20 minutes, or until puffed up and golden.
Serve in the pan, dusted with the icing sugar.