Instructions:

1. In the bowl of a stand mixer fitted with the bread hook attachment*, mix the bread flour, granulated sugar, salt, sourdough starter, whole milk, and eggs on low speed until the dough comes together. Increase to medium speed and mix for five minutes.
2. Continue mixing and add one pat of softened butter at a time until it’s fully incorporated, in 30 second intervals. Continue mixing for 5-7 minutes until the dough is smooth, tacky, and passes the windowpane test.
3. Transfer the dough to a mixing bowl, cover, and place it in a warm location to proof for about five hours until it’s doubled in size. Depending on the temperature, the dough may need longer to proof.
4. Refrigerate the dough overnight and up to 48 hours. This will improve the flavor and make shaping easier.
5. On the baking day, turn the cold dough out onto a floured work surface. Use a rolling pin to roll it out into a 12x13” rectangle and about ¼” thick. Use an offset spatula or butter knife to spread all of the Calabrian Chili Orange Spread onto the dough, leaving a ½” border on the edges. Starting at one of the shorter sides, roll up the dough into a spiraled log and seal the edges to prevent the filling from leaking out. Move it to a cutting board seam-side down and freeze it for 15 minutes to make braiding easier. Meanwhile, line a 9x5” bread loaf pan with parchment paper, with a bit of overhang on both sides.
6. Set the chilled babka log onto a floured surface and use a sharp knife to slice the babka in half lengthwise. Rotate the halves cut-side up, place one on top of the other to form an X, and wrap the two ends of the babka around each other to braid it. Pinch and slightly tuck in the ends. Then, transfer it to the prepared bread loaf pan. Braiding can be messy, but it’s okay if some of the filling leaks out during braiding.
7. Cover the pan and place it in a warm location to proof for about five hours. Proofing is complete when the dough doubles in size and feels full of air.
8. Preheat the oven to 350ºF. Once preheated, brush a light egg wash on top of the exposed dough areas of the babka and sprinkle optional pearl sugar on top for added crunch. Bake the babka for 40-45 minutes and tent it with aluminum foil if it begins to brown too quickly. The dough is ready when the internal temperature is about 195ºF.
9. As the babka bakes, make the simple syrup. Combine the sugar and water on a stovetop over medium heat and stir until the sugar is completely dissolved. Set aside to cool as the babka bakes. Use a pastry brush to brush the syrup on top of the hot babka once it’s removed from the oven. Cool for 10 minutes before lifting the babka out of the pan.