In a stand mixer bowl combine the flour, yeast, and sugar; mix the ingredients together. Form a little well in the middle of the dough and add the melted butter, milk, eggs, and salt. With a dough hood attachment, combine the ingredients together until the dough pulls together. If the dough is too sticky and is stuck to the bottom of the bowl, simply add a few tablespoons of flour and this should do the trick.
Place the dough in an oiled bowl, cover it with a kitchen towel or cling wrap and allow it to rest for 1 ½ hours, or until the dough has doubled in size.
Grease two 9×4 inch loaf pans with oil and line the bottom of each pan with parchment paper. Sets aside.
Once the dough has doubled in size, punch down the dough and with a knife, cut the dough in half and shape it into a ball and cover it with a kitchen towel until ready to use.
Roll out dough on a lightly floured surface and shape it into a rectangle measuring 14x 9 inch rectangular shape. Spread one cup of Nutella over the rectangle, leaving a ½ inch border. Sprinkle half of the chocolate chips and half the ground hazelnut on top.
Gently roll the dough into a log shape. With a serrated knife, cut the log in half lengthwise. With the cut sides up, gently cross-layer the two halves together.
Lift the dough into the loaf pan, cover it with a kitchen towel, and allow it to rest and rise for 45 to 60 minutes. Repeat the same steps with the second half of the dough.
Preheat the oven to 180°C. Place the loaf pans in the middle rack and allow to bake for 40 to 45 minutes. Allow the babkas to cool until warm, then remove them from the pan. Allow cooling completely before you are ready to serve.