Warm the milk until slightly warm to the touch. Stir in the yeast and a pinch of sugar, then let it sit for 5–10 minutes until foamy.

In a large bowl, combine flour, sugar, and salt. Add the yeast mixture, eggs, vanilla extract, and softened butter.

Mix and knead the dough until smooth and elastic, about 8–10 minutes.

Place the dough in a lightly greased bowl, cover, and let it rise in a warm place until doubled in size, about 1–2 hours.

Prepare the filling by melting the butter and dark chocolate together until smooth. Stir in powdered sugar, cocoa powder, and vanilla extract. Let cool slightly.

Once the dough has risen, roll it out on a lightly floured surface into a large rectangle.

Spread the chocolate filling evenly across the dough.

Roll the dough tightly into a log from the long side.

Slice the log lengthwise to expose the chocolate layers.

Twist the two halves together to create the classic babka swirl.

Place the twisted dough into a greased loaf pan.

Cover and allow it to rise again for 30–45 minutes.

Bake in a preheated oven at 350°F (175°C) for 35–40 minutes until golden brown.

While baking, prepare the syrup by heating sugar and water until dissolved.

Brush the warm babka with syrup immediately after baking for a glossy finish.