Scratch Chocolate Babka recipe made with a stand mixer and dough hook. This babka recipe calls for fast rising yeast. Platinum yeast works well, too. The directions are for making 4 mini loaves, but you can also make two small loaves or one giant loaf.
Yeast: If you are using regular (not fast rising) yeast, dissolve the yeast in the milk and make sure the milk is only around 115.
For the chocolate filling, I've used all kinds of chocolate and really like the results I get with melted Ghirardelli 60% Bittersweet Chips. When melted chopped chocolate is used, the filling spreads more and is a bit greasier, whereas with the melted chip mixture it doesn't ooze as much. Other recipes call for brushing the babka with butter, sprinkling with finely chopped chocolate and sugar. Those are probably great, but I have grown accustomed to the nice even distribution of melted chocolate.