How to Make It
In a small bowl, whisk the water with the yeast and 1 teaspoon of the sugar. Let stand for 10 minutes, until foamy.
In a medium bowl, whisk the eggs with the oil and vanilla. In the bowl of a stand mixer fitted with the dough hook, combine the flour, salt, cinnamon, cardamom and the remaining 1/2 cup of sugar. Mix to blend. Add the egg and yeast mixtures and knead until the dough comes together, scraping down the side and bottom of the bowl, about 3 minutes. Scrape the dough out onto a work surface and knead until smooth and slightly sticky, 8 to 10 minutes. Transfer the dough to an oiled large bowl and cover with
In a medium bowl, stir the tahini with 1/3 cup of the honey, the vanilla, cinnamon, salt and 2 tablespoons of water until smooth. In a small bowl, beat the egg with the remaining 1 tablespoon of honey and 1 tablespoon of water.
Preheat the oven to 375° and line 2 baking sheets with parchment paper. Divide the dough into 2 equal pieces. Transfer 1 piece to a lightly floured work surface and keep the other piece covered with a damp kitchen towel. Divide the dough on the work surface into 3 equal pieces. Using a rolling pin, roll out 1 piece into a 14-by-6-inch rectangle. Spread 1/4 cup of the tahini mixture on top, leaving a 1/2-inch border. Sprinkle 1/4 cup of the halvah over the tahini in an even layer. With a long side facing you, tightly roll up the dough into a log, pressing the seam and ends together to seal in the filling. Repeat with the other 2 pieces of dough, 1/2 cup of the tahini mixture and 1/2 cup of the halvah. Arrange the 3 logs on one of the prepared sheets and braid them together. Brush with the egg wash and sprinkle with sesame seeds and turbinado sugar. Repeat with the second piece of dough and the remaining filling, egg wash and toppings. Bake the challahs for about 30 minutes on the middle and bottom racks of the oven, shifting and rotating halfway through, until deep golden. Transfer to racks to cool.