In a bowl, mix the dried yeast with warm milk and sugar. let sit for 5 minutes until the yeast activates by forming small bubbles.
In a mixing bowl with a dough attachment pour the milk sugar and yeast mix. Add 2 whole eggs and one egg white. (Save one egg yolk for later)
Add the flour and salt, mix thoughouly until a dough is formed.
Add butter and mix until combined. Cover and let rise for 1 hour or until doubled in size.
Punch down the dough and place it in the fridge from 1 hour and 30 min to 24 hours.
Preheat the oven to 180°C
On a floured surface and floured hands seperate the dough in 8 small balls, tuck their edges underneath to keep a smooth surface bun shape.
Cover a baking tray with a baking sheet, place the dough balls, egg wash with the remaining egg yolk , a dash of water and a pinch of salt. sprinke some sesame seeds.
let the brioche buns proof for 45 min. Bake for 30 min to 180°C.