Prep: Bloom the yeast in sugar and water for 15 mins. Cover the dates in boiling water until soft, about 30 minutes.
113 grams water, 7 grams active dry yeast, 25 grams sugar, 12 Medjool dates
Make the dough: Once the yeast is foamy, add in the remaining dough ingredients and stir until cohesive.
113 grams sourdough discard, 1 egg, 28 grams oil, 360 grams bread flour, 6 grams salt
Knead the dough: Turn the dough out onto a clean surface. Dust the surface with a little flour if your dough is too sticky to knead. Using the heel of your hand, push the dough away from you, then fold it back over itself. Give the dough a quarter turn and repeat.
Knead the dough until smooth, 5 to 10 minutes.
First proof: Round the dough into a tight ball and proof until doubled, about 45 minutes to 1 hour.
Make the chocolate date sauce: Drain the dates and puree in a food processor with milk until smooth. Transfer to a mixing bowl and stir in the remaining filling ingredients.
28 grams milk, 50 grams brown sugar, 20 grams cocoa powder, 3 grams salt
Assemble the babkas: Line two 9 by 4-inch loaf pans with parchment paper. Roll the dough out into an 18-by-12-inch rectangle.
Spread the chocolate date filling evenly on the dough. Sprinkle cacao nibs and chocolate chips on top. Working with the longer side of the dough, roll the dough into a tight log.
60 grams cacao nibs, 160 grams chocolate chips
Cut the dough into 2 even logs. Split each log lengthwise to expose the center, twist the dough into a 2-sided braid. Transfer the dough into the prepared pans.
Second proof: Cover with plastic wrap and let the dough rise until doubled in volume, about 30 minutes to 1 hour.
Prep: Preheat the oven to 350 F while the dough proofs.
Bake: Sprinkle more cacao nibs on top (optional). Bake at 350 F for 45 to 50 minutes or until golden brown.
Meanwhile, boil sugar and water in a small saucepan over medium heat until the sugar dissolves completely.
56 grams water, 60 grams sugar
Enjoy and store: Brush warm babka with simple syrup. Allow the babka to cool slightly before slicing or it may fall apart. Store leftover slices in an airtight container for up to 3 days at room temperature.