Activate the yeast:
--In your stand mixer bowl, whisk the warm milk, yeast and half the sugar together.
--Let it sit for 5 minutes until frothy.

Mix the Base:
--Add the remaining sugar, flour, salt, and 3 eggs to the bowl.
--Using the paddle attachment, mix on low speed until a thick, shaggy dough forms.

Incorporate the Butter:
--Switch to the dough hook.
--Turn the mixer to medium speed and add the softened butter a few cubes at a time.
--Wait until each addition disappears into the dough before adding more.

Knead and Fold:
--Once all the butter is in, knead for 10–12 minutes on medium-high speed.
--The dough will be very sticky at first, but it will eventually pull away from the sides of the bowl and look shiny and smooth.
--Fold in the chocolate chips on low speed just until distributed.

First Rise:
--Place the dough in a greased bowl, cover it with plastic wrap, and let it rise in a warm spot for 1.5 to 2 hours until doubled in size.
--(Optional: For a tighter crumb structure and deeper flavor, punch the dough down after this rise and chill it in the fridge overnight before shaping).

Shape the Loaf:
--Turn the dough onto a lightly floured surface.
--Divide it into 3 equal pieces, roll each into a smooth ball, and place them side-by-side inside a greased 9x5-inch loaf pan.

Second Rise:
--Cover the pan loosely with a damp towel or plastic wrap.
--Let it rise a second time for 1 hour until the dough puffs up just above the rim of the pan.

Bake:
--Preheat your oven to 175°C.
--Gently brush the top of the loaf with your egg wash.
--Bake for 35 to 40 minutes until deeply golden brown.
--If the top darkens too quickly, shield it loosely with aluminum foil halfway through baking.

Cool:
--Remove from the oven and let it sit in the pan for 10 minutes before turning it out onto a wire rack to cool completely before slicing.