Prepare a “ferment”: dilute the yeast in part of the warm milk and a tablespoonful of flour and leave until it has doubled in volume.
Put the rest of the milk, the rest of the flour, the sugar, salt, eggs and ”ferment” in the food processor and work until the dough is smooth and shiny, around 10 minutes at medium speed.
Add the creamed butter and work the dough until it is elastic and comes away from the sides of the bowl.
Cover with a damp cloth and leave to rise until it has doubled in volume.
Gently flatten the dough, fill the mould half-way up and leave at room temperature until it has doubled in volume once again.
Bake at 180º C for around 50 minutes. Leave to cool, cut off any excess dough overhanging the mould, and turn out the brioche.
Serve the brioche with jam or fromage frais.