Open a large zip-top bag and place it on the counter. Add the yeast, water, egg, orange zest, sugar, salt, vanilla and butter. Close the bag and squeeze to mix thoroughly.

Open the bag and add the flour. Squeeze and knead until the dough is a somewhat even consistency. Place the bag in a bowl of warm water to rise for 1 hour.

Remove the dough and place on a well-floured surface. Roll out the dough into a large rectangle.

Spread nutella on the dough, avoiding 1 inch around the edges. Sprinkle the chocolate chips evenly.

Starting from one of the long edges of the dough, roll up the dough into a rope. Cut the dough in half down the middle of the rope. Place one strand on top of the other to create a large X, then twist the remaining ends.

Place in a greased 8-inch loaf pan, cover and place in a warm part of the kitchen to rise for one hour or until doubled in size. 

Preheat the oven to 350℉ / 175℃.

Bake for 40 minutes.

Remove the babka from the oven then place a small sauce pan on medium heat. Add the water and sugar then bring to a simmer. Once sugar is dissolved, brush the syrup on top of the babka.