To prepare the dough, mix milk, sugar and yeast in the standing mixer. Let sit for 10 minutes, or until you see foam at the stop.
With a paddle attachment, beat in eggs, one at a time, until the mixture becomes light and creamy.
Add the flour and salt, continue mixing until the flour is incorporated.
When the mixer is running, slowly add small pieces of softened butter.
Let the mixer knead the dough for another 5 minutes. The dough will become very stretchy and sticky.
Place the dough in a lightly oiled large bowl. Cover the bowl with a plastic wrap and let rise in a warm place for 2 hours.
Leave the dough in refrigerator overnight.
The next day, remove dough from the fridge. Let it come to room temperature.
Grease 2 loaf pans and line with parchment paper. Set aside.
Move the dough to a lightly floured surface. Divide the dough into 10 pieces and roll them into balls. Place 5 dough balls in each prepared pan. Cover with tea towel and let it rise for another 2 hours.
Preheat oven to 350F.
Mix egg yolk and cream. Lightly brush the egg wash over each loaf. Bake for 30 to 35 minutes until the loaves are golden brown on top.
Remove from oven and let cool slightly before slicing.