In a stand mixer, mix warm milk, yeast, and a pinch of sugar. Let sit for 5-10 minutes until frothy.

Add remaining sugar, eggs, vanilla, flour, and salt. Mix on low with a dough hook until a shaggy dough forms.

With mixer on medium-low, add softened butter one tablespoon at a time until fully incorporated. Knead for 10-15 minutes until smooth and elastic.

Place dough in an oiled bowl, cover, and refrigerate overnight (or let rise at room temp for 1.5-2 hours until doubled).

Melt butter and chocolate chips for the filling. Whisk in powdered sugar, cocoa powder, cinnamon, and salt. Let cool slightly.

Roll dough out into a 12x18 inch rectangle. Spread chocolate filling evenly and sprinkle with half the pistachios.

Cut the dough vertically into 6 strips. Stack the strips, then cut the stack horizontally into 6 equal squares.

Place the dough squares sideways (like an accordion) into a greased and parchment-lined 9x5-inch loaf pan. Cover and let rise for 45-60 minutes.

Bake at 350°F (175°C) for 40-45 minutes until golden. Tent with foil if browning too quickly.

Simmer water and sugar to make a simple syrup. Brush over the hot bread immediately out of the oven. Cool for 20 minutes before removing from pan.

Melt remaining chocolate chips with coconut oil. Drizzle over the cooled loaf and sprinkle with remaining chopped pistachios.