• Place 4 cups (560 grams) of flour, sugar, yeast, salt and zest in the bowl of a stand mixer fitted with the paddle attachment.
• Add the warm milk and stir until moistened. You can use the paddle for this or just do it by hand. Most of the work will be done with the dough hook. Add the eggs and stir until blended.
• Switch to the dough hook and begin kneading. With the mixer going, add the oil, then add the butter. Let the machine knead until the butter is incorporated. At this point you should have a very soft, buttery dough which will most likely need at least ½ cup more flour. Continue kneading with the dough hook.
• Add remaining 70 grams flour gradually. The dough will clear the side of the bowl with each addition of flour, then begin to stick again. Continue kneading for about 8 minutes or until dough is smooth and has some elasticity to it. It will never completely clear the side of the bowl.
• Place the dough in a lightly oiled bowl. Cover with greased plastic wrap and let rise in a warm place until doubled -- about an hour. Prepare loaf pans, filling and crumb topping while the dough rises.
• Prepare the loaf pans by greasing with a generous amount of butter, lining with strips of parchment and greasing again. The pans need a lot of grease because preserves are sticky!

Filling and Crumb Topping

• Melt the butter in a saucepan or in a microwave-safe bowl. Stir in the preserves. Set aside to cool
• I don't always use crumb topping but it's a nice addition. To make it, just mix together powdered sugar and flour and mash in salted softened butter until crumbly. Keep chilled until ready to use.

Assembly

• On a pastry mat, you probably won't even need flour because of all the butter, pat half of the dough into a 10x15 inch rectangle.
• Spread half of the preserves mixture over the rectangle, leaving about a ½ inch border. Sprinkle chocolate over the preserves. Brush the border with some egg wash.
• Starting on the long side, roll the dough into a jelly roll and pinch the ends closed. Cut the log in half and set the halves on a baking sheet or tray that can fit in the refrigerator. Repeat with remaining dough, setting cut logs on the same baking sheet.
• Refrigerate or freeze the logs of dough for about 30 minutes. This makes them easier to slice.
• When both logs are very firm, take two out of the refrigerator. Twist them together and press into the pan. Alternatively, you can split the logs lengthwise to make 4 pieces. Twist 2 of the pieces and lay them in the pan, then twist the other two and lay them in the pan, pinching ends to make a loaf. Remove the other two logs from the refrigerator and repeat.
• Cover with a well greased piece of plastic wrap and let rise in a warm place for about 45 minutes.Dough should rise a bit, but will not completely double.
• Meanwhile, preheat the oven to 350 degrees F. When ready to bake, brush the loaves with egg wash. Sprinkle the crumble over the top along with a little extra chocolate and/or some almonds or nuts if you have some.
• Bake loaves for about 55 minutes or until brown and baked through.
• Allow the loaves to cool for about a half hour in the pan, then carefully loosen with a knife and remove.