• Recommended: Refrigerate the dough for about 60 minutes before shaping the babka.

Make The Filling

• Measure the walnuts, almonds, pistachios, cinnamon, sugar and orange zest into a bowl of a food processor.
• Process until you have a fine mixture. Set aside.

Make The Syrup

• Measure the water, and honey in a medium sauce pan, then add the cinnamon stick and orange peel.
• Bring to a boil over medium-high heat.
• Reduce heat to low and simmer for 5-7 minutes.
• Remove from heat and set aside to cool, refrigerating until use.

Shaping

• Grease one large tube pan with cooking spray, or grease two 9x5 loaf pans and line them with parchment paper
• Remove the dough from the refrigerator and punch it with your fist.
• Using a rolling pin, roll the dough into a 24x18-inch rectangle.
• Brush the top of the dough with the half of the melted butter.
• "Layer the dough with the nut mixture, then sprinkle the rest of the batter over the nuts and gently press it with your fingers into an even layer.
• Roll the rectangle into a sprial log (like a jelly roll) starting from the long end.
• Use a knife to cut the log at the center.
• Gently twist the two pieces around each other. This step can get pretty messy, and that is ok.
• Gently lift the twisted log and place it in the prepared pan.
• Sprinkle back any filling that may have spilled out during the twisting step.
• Brush the raw dough with the egg yolk, cover it with plastic wrap (making sure it does not tough the dough) and set aside to rest for 90-120 minutes.
• Bake at 350F (180C) for 38-45 minutes, until the internal temperature reads 190F (88c). Top the pan with a piece of aluminum foil if you notice that the top is getting too dark before the bread is ready.
• Remove from the oven and immediately brush with the syrup (use a much or as little as you want, you don't have to use the whole syrup).
• Allow it to cool in the pan for 20-30 minutes than invert to a plate and serve.