Prepare all ingredients:
Prepare the levain: In a small bowl, dilute the yeast with warm milk and add a bit of flour until you obtain a small soft dough.
Cover and leave to rest until doubled in volume.
In a pan, place the flour and salt. Make a hole in the center and place the sugar, softened butter and eggs in it.
Mix all together and add the levain. Knead the dough well and form a ball.
Cover with a cloth and leave to prove for about 3 hours.
Roll out the dough using a rolling pin and make a round shape that you place in a silicone cake mold of 28 cm.
Leave to rest another hour. Beat the egg and the filling with milk and spread on the pastry. Sprinkle with brown sugar and small knobs of butter.
Bake in medium oven 150°C for about 25 minutes.
Serve warm preferably.