Meanwhile, stir butter and remaining sugar into remaining milk; heat until butter is melted. Let cool to lukewarm.
In large bowl, whisk 2-1/2 cups (625 mL) of the flour, lemon rind and salt. Make well in centre; add eggs, milk mixture and yeast mixture. With wooden spoon, stir to form soft, slightly sticky dough that comes away from side of bowl.
Step two: Turn out onto floured surface; knead for 2 minutes or until smooth, adding enough of the remaining flour as necessary. Place in greased bowl, turning to grease all over. Cover and let rise in warm draft-free place until doubled in bulk, about 1 hour.
