In a bowl, dissolve Active Dry Yeast (1 package) in Water (1/4 cup). Let stand until foamy, 10 minutes.
Stir Milk (1/2 cup), Granulated Sugar (1/2 cup), Orange Juice (1/2 cup), Ricotta Cheese (1/2 cup), Sunkist Orange (1 tablespoon), Salt (1/2 teaspoon) and Egg (1) into the yeast mixture.
With a mixer slowly mix 2 cups of All-Purpose Flour (3 1/2 cup) into above mixture until moist dough has formed. Beat in remaining flour until the dough becomes stiff.
Turn the dough out onto a lightly floured surface and knead until smooth and elastic, about 5 minutes.
Place the dough into a large oiled bowl. Cover with a damp towel or plastic wrap, and let rise in a warm place until doubled in size, about 1 ½ hours.
Punch the dough down and knead for another couple of minutes. Divide into 3 equal pieces. Roll each piece into a 20 inch long rope.
Braid the ropes together.
Coil the braided dough in a prepared spring form pan, or pan of your choice, that has been buttered. Cover loosely with a damp cloth and let rise again for about 30 minutes or until doubled in size.
Preheat oven to 425 degrees F (220 degrees C).
Beat an Egg (1). Use beaten egg as a glaze. Brush the dough with glaze.
Bake until the top of the cake is golden brown, about 25-30 minutes. Turn the cake out on a wire rack.
Prepare the icing. Combine Powdered Confectioners Sugar (1 cup) and Orange Juice (1 1/2 tablespoon). Drizzle over the warm cake.