Sift the flour. Dissolve the yeast in water. Wait for about five minutes for the yeast mixture to bubble.
Once the yeast mixture becomes frothy, add it to a fourth of the flour and make a small ball. Cut across the top of the ball so that the ball can rise.
Drop the small ball into a large bowl of hot water. The water must just be hot enough for you to dip your fingers in. The temperature must ideally be between 105-1100F.
Once the ball is double in size and has risen to the surface, it is ready to be folded into the dough later.
In the meantime, take the rest of the flour in a bowl and make a well in the center. Beat the eggs, sugar, salt and the milk together with a fork.
Pour the egg mixture into the flour and combine to form a dough.
Knead the dough thoroughly until elastic. When you pull the dough apart, it should taper off to a thin ribbon that is translucent. The dough will be sticky but it must be shiny at this point.
In another bowl or a stand mixer, cream the butter. Gradually work the butter into the dough.
After kneading the dough with the creamed butter, the dough at this stage should be pliable and glossy.
Drain the soaked sponge ball using a slotted spoon.
Carefully, cut the sponge and fold into the dough. Fold in very carefully ensuring that the sponge if thoroughly combined with the dough.
Knead the dough well into a large ball. Place in a greased bowl.
Sprinkle on top with flour. Cover with a damp cloth and leave it in a warm place to rise at room temperature for about 2 hours.
When the dough has doubled in bulk, knock it down, pull from the sides to the center. Turn it over and sprinkle again with flour. Cover with a damp cloth and refrigerate overnight for 8 hours.
The following day, briefly knead the dough. Make small balls and place two per depression in the greased mini loaf tin. Let the brioche rise again for 20 minutes in a warm place. Brush with heavy cream mixed with salt or egg wash. Bake at 4250F for 15-20 minutes until golden brown.