Melt the butter in a saucepan. Add the milk and heat gently. Cool to room temperature.
Beat the egg and add to the milk.
In a small bowl, dissolve the yeast in the water. (You can check the temperature with a food thermometer, or by putting a drop on your wrist. If it feels comfortable to your wrist, the temperature is good to go.)
Mix the sugar, salt, mahlab, fennel seed, anise seed, ginger and baking powder together in a small bowl. Place 5 cups of the flour in a large mixing bowl. Combine the sugar-and-spice mixture into the flour. Add the milk-egg mixture. Stir in the dissolved yeast and mix well.
Place the dough on a lightly-floured work surface and knead until it is smooth and elastic, about 10 minutes. If the dough seems a bit sticky, work in up to 1/2 cup flour that wasn't used earlier.
Place the dough in a large, clean bowl, cover with plastic wrap, and then cover that with a towel. Allow to rise for 2 hours.
Gently deflate the dough. Break off a piece of dough about the size of a golf ball. Roll it into a thin rope about 16 inches in length. Break off about one-third of the rope. Shape the longer piece of dough into a horseshoe "U" shape. Place the shorter piece of dough in the center of the "U" and braid the three strips of dough into a chorag.
Place the braided chorag on an ungreased baking sheet. Continue to shape the dough until the baking sheet is full. (Don't place chorag too close to each other. Give them room to expand while they bake. If necessary, use extra baking sheets.) Let the chorag rise on the baking sheet for 1 hour.
While the shaped dough is rising, place racks in the top and bottom thirds of the oven and preheat the oven to 375 degrees F.
Brush the tops of the chorag with the egg wash. Place one baking sheet on the bottom oven rack and bake until the bottoms of the chorag are golden, about 15 minutes.
Transfer the baking sheet to the top rack and bake until the tops of the chorag are golden, about another 5 minutes. Transfer the rolls to cooling racks. Continue this procedure until all the sheets of chorag have been baked.
Store the completely cooled chorag in a container with a tight-fitting lid, or place in freezer bags and freeze until ready to serve. They can be thawed in the microwave: wrap each chorag in a paper towel and microwave on low to medium power for about 30 seconds or until defrosted.