Warm your milk, about 45 seconds in the microwave. Add milk, sugar and starter into your mixing bowl. Using a dough whisk make sure everything is incorporated.
Then add your flour and egg. Using your dough whisk mix into a shaggy dough.
Cover and let rest for 30 minutes.
Once rested you can place on your kitchen aid mixer, put your dough hook in.
Sprinkle salt all over your dough.
Cut your softened butter into sections, approximately 1 tbsp each. (Sometimes I do even smaller)
Slowly add 1 Tbsp of butter at a time and start your kitchen aid mixing the dough.
Once all is in corporated, it will look sticky and should be soft. If it is overly sticky you can splash a handful of flour on and mix.
Let bulk ferment 8 hours (or overnight)
Once it has risen, take out of bowl and place on silicone mat.
Divide dough into sections and weigh them. I typically make each one about 130 grams.
Shape your dough into burger buns
Place shaped on your parchment paper lined baking sheet. Cover and let rise for 2 hours.
Egg wash the tops of your buns
When they have doubled place in a 350℉ heated oven for 30 minutes.
Optional- Brush the tops of your buns with butter.