To make the starter: Combine the starter ingredients, cover, and leave at room temperature overnight., To make the dough: Mix the starter with the dough ingredients, kneading until elastic and satiny. Let the dough rise in a greased, covered bowl for 1 to 2 hours, until puffy., Divide the dough into three pieces. Flatten each piece into a 6" x 12" rectangle., Mix the filling ingredients together, and spread each rectangle with some of the filling., Starting with a long edge, roll each rectangle into a log. Braid the logs together., Cover the braid, and allow it to rise for 1 to 2 hours, until puffy., Preheat the oven to 350°F., Combine the egg white with 1 tablespoon water, and brush onto the braid. Sprinkle with pearl or sparkling sugar., Bake the braid for 30 to 35 minutes, until golden brown; a digital thermometer inserted into the center should register 190°F., Remove the bread from the oven, and transfer it to a rack to cool., Yield: one 12" to 14" loaf.