This was a while ago, but I made a loaf of challah, and having had success with babka in the past, decided why not. Melted some baking choc and thoroughly mixed in sugar and honey. I actually made two loaves: the one in the pic was the first one. For it I just flattened the logs, spread the chocolate in like peanut butter, then pinched the logs shut (though they split back open during rising, I figured it would look pretty and I Meant To Do That). But for the second loaf, when the chocolate had cooled down, it had basically turned into chocolate play dough! It was remarkable how non-sticky this log of sugar and chocolate became. I guess just go heavy on the sugar, refrigerating it would probably also help, but I just had it sitting on the counter!