Wake up the yeast by stirring warm milk and a spoonful of sugar together, then sprinkle in the yeast. Let it sit for 5 to 8 minutes until foamy.

In a big bowl, mix flour, remaining sugar, and salt. Add the yeast mixture, eggs, vanilla, and stir until a shaggy dough forms.

Add softened butter gradually while mixing until the dough looks smoother and slightly sticky but pulls away from the bowl.

Cover the bowl and let it rise until doubled, about 60 to 90 minutes.

Melt the butter and chocolate together until smooth, stir in cocoa, powdered sugar, and a pinch of salt. Allow to cool slightly.

Flour your counter and roll the dough into a rectangle, roughly 10 by 14 inches. Spread chocolate filling over, leaving a border.

Roll it up starting from the short side into a tight log. Chill for 10 minutes if it feels too soft.

Cut the log lengthwise and twist the two strands together with cut sides facing up. Tuck into a greased loaf pan.

Cover and let it puff up for 30 to 45 minutes until fuller and jiggle slightly.

Preheat the oven to 350°F (175°C). Bake for 35 to 45 minutes, covering with foil if the top browns too quickly.

Check doneness by inserting a skewer. It should come out mostly clean.

Optional: Brush the warm loaf with simple syrup for shine and softness. Wait at least 20 minutes before slicing.