Homemade Brioche Burger Buns

Homemade Brioche Burger Buns 
Ingredients : - 

1 cup  milk 
2 tbsps water 
2 tbsps dry active yeast 
2 tbsps sugar 
2 eggs - beaten 
2 cups bread flour 
1 cup whole wheat flour 
1 tsp salt 

For the top : -
1 egg yolk - beaten 
3 tbsps toasted sesame seeds 

Method : - 

In a small pot , scald the milk (Scalding means heating until small bubbles form around the edges of the pan and steam rises from the surface m but never boiling).
Remove the milk from the heat and then add the water. Stir and let it sit for a while ( 2 minutes) and then add the sugar and yeast to bloom for about 5 minutes. It should be foamy on the surface. Then add  the butter and eggs. Add the salt to the flour mixture and then incorporate the dry ingredients into the yeast mixture. 
Knead the dough for 8- 10 minutes and the dough will be sticky. Place the dough in a well oiled bowl and cover with a plastic wrap loosely and set it aside to proof for 2 hours until doubled. 
Punch the dough down very well and gather into a ball. Divide the dough into 8 small equal portions.  
Shape the balls by hand into perfect balls  and arrange them on the baking tray about 1 inch apart . Cover loosely with plastic wrap and let it proof for another 1 hour. 
Preheat the oven to 200 C / 400 F. 
After 30 minutes , brush all the buns with some egg wash and sprinkle some toasted sesame seeds on top of each bun before baking. Bake the buns at 200 C for 25 minutes till golden brown.