Sweet, soft, enriched dough swirled with chocolate and baked to perfection, sourdough babka comes together with simple ingredients and natural leavening through fermentation. This rich, sweetened loaf bursts with the buttery flavor of brioche, sourdough tanginess, and a delicious chocolate filling spiraled through the layers.
Feed your starter in the evening. In the morning, it should be very bubbly and active. Combine all dough ingredients in the bowl of a stand mixer with a dough hook attachment and knead until smooth and glossy. The dough will be very wet, but after 10-15 minutes in the stand mixer, it will come together. Don’t add more flour, or the texture may be thrown off.
Cover the babka dough with plastic wrap, a damp towel, or a tight-fitting lid and place in a warm spot for 6-8 hours (or until doubled) for bulk fermentation.
After the bulk fermentation, place the dough in the refrigerator for a few hours (or overnight) so it will be nice and stiff for shaping. Even a little fridge time makes shaping easier, as it does with brioche and challah.
To make the chocolate filling, add the cocoa powder, sugar, chocolate chips, and softened butter in a small small pot. Heat on low until melted, stirring occasionally.
Place the chilled dough on a lightly floured work surface, and roll it into a 10" by 14" rectangle. Trim the edges to keep a straight edge, if needed.
Spread the chocolate filling evenly over the dough, spreading to the edges, leaving one inch of space at one of the short ends of the rectangle. Sprinkle the chopped semi-sweet chocolate over the chocolate filling. Roll the dough up from the opposite short side, pressing the end in to seal. Once rolled up, use a sharp knife to cut in half down the length. Twist the halves into a braid and add them to your loaf pan.
Let your babka rise in the loaf pan, loosely covered, for about 4 hours or until doubled in size.
After doubling, preheat the oven to 350 degrees Fahrenheit. Make an egg wash by whisking one egg with a little bit of water. Brush the egg wash over the top of the babka and bake for 40-45 minutes until golden. Let the loaf cool before slicing.
Notes
Feed your starter the night before you plan to make this, so it is nice and bubbly! If you don’t have bread flour, you can use all-purpose. It will not be quite as soft as using bread flour, but it will still turn out well. The bread flour also helps it rise more.This is a wet, sticky dough. Too much flour will give you a tougher bread rather than something light and fluffy, so refrain from adding more to reduce the stickiness.Enriched dough takes longer to rise. Warmer temperatures speed up the rise time.Once you have your babka filled and rolled up, move it to a piece of parchment paper before cutting it and braiding. Then use the parchment paper to lift the babka into your loaf pan (and reduce the mess!).