Far breton classique

03 — Method

1. Preheat the oven to 230 °C (450 °F). Put the 40 g (1½ oz) of salted butter in pieces in the gratin dish and place it in the oven for a few minutes until it melts, foams and turns nutty brown, coating the whole bottom.
2. Meanwhile, whisk the flour, sugar and the 2 packets of vanilla sugar together in a large bowl.
3. Add the 4 eggs one at a time, whisking hard in the same direction, until thick, smooth and lump-free (it will be stiff at this point — the milk loosens it).
4. Whisk in the whole milk in 3 additions until the batter is completely smooth and runny, like crêpe batter.
5. Take the hot dish out, lower the oven to 200 °C (400 °F) and pour the batter straight onto the browned butter (add the prunes or raisins now, if using).
6. Bake at 200 °C (400 °F) for 30 minutes until set, golden on top and slightly wobbly in the center. Let cool slightly before eating.