Collect all the ingredients and bring them to room temperature.
Grate the orange rind and extract the juice.
Add the yeast in lukewarm water with 1 tsp of sugar and keep it until frothy.
Now mix a little flour in it along with warm milk and set aside to make the pre-ferment.
In a large bowl combine 2 cups flour, 1/4 cup sugar and 1/2 tsp salt.
In another large bowl whisk together the pre-ferment, eggs, Orange juice and zest until well blended.
Add the flour little by little and continue stirring until the flour is nicely blended into the liquid. Set aside for 15 minutes.
Now start adding butter little by little while kneading the dough.
Remove it on a dusted surface and knead well . You may find it sticky and you can add a little flour until it is manageable and doesn’t stick.
Once the dough is smooth roll it into a rectangle. Wrap it in a cling film and refrigerate for 4 hours. (you may refrigerate overnight also for best results)
For the filling heat the chocolate, milk and butter in a double boiler over low heat. Stir constantly until the mixture is smooth. Remove the top bowl from the heat. whisk in the egg white and 1/4 cup sugar until smooth.
Add in the cocoa powder and continue to whisk until combined.
Line a rectangle baking tray with plastic wrap and spoon the chocolate mixture on it spreading with a spatula.
Place another plastic sheet over it and refrigerate the pan for 4 hours.
When you are ready to bake the buns remove the dough and the filling from the refrigerator.
Roll out the dough into a large rectangle.
Remove the top sheet from the chocolate tray and place the filling on the rolled dough leaving 1 inch on top and 5-6 inches on the sides.
Fold the sides over the filling and pinch the edges to seal
Roll the dough carefully, fold it and roll again . Repeat 3-4 times .
Finally roll it like a cylinder.
Cut about 2 inch slices using a sharp knife or thread.
Place them in greased muffin tins. Set aside covering loosely with a plastic for 1 hour Orr until doubled in size .
