In a large mixing bowl, combine the flour, sugar, salt, yeast, warm milk, and sourdough starter. Mix until a soft dough forms.

Add the softened butter and knead for about 10 minutes until smooth and elastic.

Place the dough in a greased bowl, cover it with a kitchen towel, and let it rise in a warm area for about an hour or until it doubles in size.

Once risen, punch down the dough and roll it out on a lightly floured surface into a rectangle (about 12x18 inches).

Sprinkle cocoa powder evenly over the rolled-out dough, followed by the chocolate chips. Leave a small border around the edges.

Starting from one long edge, tightly roll the dough into a log. Pinch the edges to seal.

Cut the log in half lengthwise, exposing the chocolate swirl, and braid the two halves together, creating a twisted loaf.

Place the twisted loaf into a greased loaf pan. Cover with a towel and allow it to rise for about 30 minutes.

Preheat the oven to 350°F (175°C). Brush the loaf with the egg wash and bake for 30-35 minutes, or until golden brown and a toothpick inserted in the center comes out clean.

Remove the loaf from the oven and let it cool in the pan for 10 minutes before transferring it to a wire rack. Slice and savor every blissful bite!