Mix the yeast, lukewarm milk, and sugar, and let it sit for 5 minutes until foaming.
In the bowl of a stand mixer add flour, salt, and eggs. Once the yeast mixture is foamy add to the flour mixture as well. Mix to combine using the dough hook on the stand mixer.
Add the butter in pieces and knead for another 15 minutes at speed level 2 (your dough should be sticky but comes easily from the bowl using a silicone spatula).
Place the dough in a greased bowl, cover with a damp tea towel, and let it rise at room temperature for one hour. Refrigerate for 4-16 hours. This is what makes your brioche soft & airy.
Take the dough out of the fridge, place on a lightly floured surface, divide into six pieces. Gently form each piece into a small roll and place to fill a 9x5 loaf pan. Let rise at room temperature for another 1.5-2 hours
Preheat the oven to 400 F. Bake for 30-35 minutes until brown. Allow the brioche to cool down on a cooling rack before slicing.