Heat milk to 100°.  It should be warm to touch, like hot tap water.

In bowl of food processor or stand mixer, add 1 cup of flour, the yeast and sugar.  Pour warm milk over the yeast.  Let it soak up for a minute, then process until combined.  Add remaining flour and salt.  Process until combined.

Add eggs one at a time and mix until combined.

Cut butter into chunks and add gradually to mixture. Using a rubber spatula, plop mixture into a bowl, cover with plastic wrap and let rise until doubled, about 1 hour, then punch it down. (or if you are in a hurry, got to step number 5 and let rise once in the muffin tin.)

Grease cups in a muffin tin.  Spoon brioche mixture into muffin cups, filling them 1/2 full.

Brush brioche with egg wash and let rise until doubled.  Bake at 400° for about 15 minutes or until buns are golden brown.

Loosen the buns from the muffin tin and serve or store in an airtight container.