In a small bowl, mix the yeast with warm milk and 1 tablespoon of sugar. Let it sit for 5–10 minutes until it becomes frothy.

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

Knead the mixture for 8–10 minutes until the dough is smooth and elastic. Cover the dough with a clean kitchen towel and let it rise in a warm place for 1.5–2 hours until it doubles in size.

In a separate bowl, combine the melted chocolate, hazelnut spread, cocoa powder, sugar, and crushed hazelnuts until the mixture is smooth.

Roll out the risen dough into a large rectangle, approximately ½ cm thick.

Evenly spread the filling over the rolled-out dough.

Roll the dough tightly into a log, then cut it lengthwise into two strips. Twist the two strips together, keeping the cut sides facing up.

Place the twisted dough into a greased loaf pan. Cover it and let it rise again for 45–60 minutes. Preheat the oven to 350°F (180°C). Bake the babka for 35–40 minutes until it turns golden brown.

While the babka is baking, prepare the syrup by heating the water, sugar, and vanilla extract in a saucepan until the sugar dissolves. Let the syrup cool slightly.

Once the babka is out of the oven, brush it with the prepared syrup to keep it moist and give it a glossy finish. Allow it to cool slightly before slicing. Enjoy!