In a small bowl sprinkle the yeast and a pinch of sugar over the warm water and stir to dissolve. Let stand until foamy, about 10 minutes.
Combine the butter, sugar, salt, vanilla, milk, eggs, cocoa powder, and 1 cup of flour and mix well.
Add the yeast mixture and stir to combine. Gradually add the remaining flour.
Turn the dough out onto a lightly floured surface and knead until smooth and elastic, 8 to 10 minutes by hand or 5-7 minutes with a stand mixer.
Shape the dough into a round and place it in a large greased bowl, turning once to coat.
Cover with a plastic wrap and allow the dough to rise at room temperature until doubled, approximately 1-1/2 hours.
While the bread is rising, prepare the filling. In the bowl of an electric stand mixer, combine the farmers’ cheese, sugar, sour cream, egg, vanilla extract, and melted chocolate chips. Beat together until smooth. Set aside.
Turn the dough onto a lightly floured surface and pat it into a 10-inch by 12-inch rectangle. Spread the 2 tablespoons of melted butter over the surface of the dough and then spread the filling mixture over the butter.
Roll the dough up like a jelly roll, starting from the long end and pinch the seams and ends closed; twist the dough 6 to 8 times to form a rope (much like wringing out a towel).
Arrange the rope of dough on the parchment-lined baking sheet. Cover loosely and let the roll rise for 1 hour.
Preheat the oven to 350 °F. Bake for 40 to 45 minutes. Remove from the oven and let stand for 5 minutes; invert onto a wire rack. Allow the chocolate babka to cool for at least 2 hours before slicing.
Notes
Tips for success:Knead the dough properly: Proper kneading is crucial to developing gluten, which gives the bread structure and texture. Knead the dough until it becomes smooth, elastic, and slightly tacky. This usually takes around 8-10 minutes of kneading by hand or 5-7 minutes with a stand mixer.Don't overfill the dough: When spreading the chocolate filling on the rolled-out dough, make sure to leave a border around the edges. Overfilling can cause the filling to leak out during baking, resulting in a messy babka.Create tight rolls: When rolling the dough into a log shape, make sure to roll it tightly. This will help prevent the filling from escaping. I make my first twist in the center and work to each end.Let the bread cool completely: Bread continues to cook internally even after it is removed from the oven. During the cooling process, the residual heat evaporates moisture, allowing the bread to set and firm up. Slicing into hot bread can result in a gummy or doughy texture, as it hasn't had enough time to fully bake and set.
This recipe was calculated using the exact brands and measurements I used to make this recipe. If you are following a strict diet please note changing anything will cause the nutritional info to change. My calculations are intended as a guide only.