In a large bowl, dissolve the yeast in the warm water. Let stand until foamy 5-10 minutes.
Stir the warm milk, orange juice, ricotta cheese, orange zest, salt and 1 beaten egg into the yeast mixture. Beat 2 cups flour into the yeast mixture until a wet dough forms. Knead in enough of the remaining flour, ½ cup at a time, until a stiff dough forms.
Turn out the dough onto a lightly floured surface and knead until smooth and elastic, 5-10 minutes, adding more flour as needed to prevent sticking.
Place the dough in a large greased bowl, turning to coat all sides. Cover and let rise in a warm, draft free place, until doubled in bulk, about 1-1/2 hours.
Grease a 10” springform pan. Punch down dough. Turn onto a lightly floured surface and knead for 1-2 minutes. Divide the dough into 3 equal pieces. Roll each piece into a 20” long rope.
Coil braid the 3 pieces together and place in prepared pan, tucking ends under. Cover and let rise in a warm, draft free place until doubled in bulk, about 30 minutes.
Preheat oven to 425ºF. Brush the dough with the glaze. Bake until the top of cake is golden brown, 25-30 minutes. Turn the cake out onto a wire rack to cool.
Icing: Ina small bowl, add the confectioners sugar and orange juice, stirring until smooth, Spread icing over warm cake.