Dark Chocolate, Tahini, and Halva Brioche Babka

BREAD DOUGH

1. In a small bowl, combine the yeast, milk and 2 tablespoon of the sugar. Mix well, and leave to sit for 10-15 minutes, or until foamy.
2. In the bowl of a stand mixer fitted with the dough hook, combine the flour, salt, and remaining 2 tablespoon sugar. Mix briefly to combine. Add the eggs, vanilla, and foamy yeast mixture to the bowl. Mix on low for 2-3 minutes, until the dough is starting to come together. It may look slightly dry but do not worry - it will mix together nicely in the next steps. Increase the mixer speed to medium, and mix for another 10 minutes, until the dough is soft and smooth. 
3. Reduce the mixer speed to low, and add the butter a little at a time, waiting until it is fully incorporated into the dough before adding the next piece. This process should take 3-4 minutes. Once the butter is fully incorporated, increase the mixer speed to medium, and mix for a further 5 minutes, until the dough is very soft and smooth. 
4. Transfer to an oiled bowl, and cover tightly with plastic wrap. Place in a warm spot until doubled in size, approximately 1 - 1 ½ hours. Alternatively, place the bowl in the fridge, and do the first rise overnight.

TAHINI DARK CHOCOLATE FILLING

1. Combine all of the filling ingredients in a heat safe bowl, and place over a pot of simmering water to create a double boiler setup. Ensure that the bowl does not touch the water. Heat, stirring occasionally with a spatula, until the chocolate has melted and the mixture has combined. Do not whisk or you could cause the tahini to seize. Transfer into a jar and allow to sit at room temperature for at least an hour, or overnight. Store at room temperature.

ASSEMBLY

1. Line a baking sheet with parchment paper.
2. Turn out the dough onto a lightly floured surface. Roll into a rectangle 16” x 24”, squaring off with a bench scraper as you roll to make sure it is as even as possible. Using an offset spatula, spread the half a cup of the filling mixture over the surface of the dough, then sprinkle with the halva.
3. Starting from the long side of the dough, roll up the dough into a tight spiral. Measure the length of the sausage of dough, then cut in half so it is in two sausages. Place these pieces side by side on the lined baking sheet, cover with plastic wrap, and chill for an hour. You can skip this step if you did an overnight rise.
4. Line two loaf pans with a parchment paper ‘sling’. Remove the chilled dough sausages from the fridge. Working with one at a time, using a sharp knife, cut the first piece in half, lengthwise, and then cross the pieces over each other, and then cross over two more times to form a twist (this video also explains well). Place into the loaf pan, tucking the ends under slightly if needed. Repeat with the second half of the dough.
5. Lightly cover the loaf pans in plastic wrap, and place in a warm place to rise for an hour to 90 minutes, or until the dough springs back lightly when pressed. While the loaves are proofing, preheat the oven to 350˚f / 180˚c. 
6. Brush the loaves lightly with egg wash. Bake for 40-45 minutes, or until the loaves are golden brown and the internal temperature registers 200˚F / 90˚c. Remove from the oven and cool completely before slicing. Store leftovers in an airtight container, or wrap tightly before freezing.