In a large bowl, stir 2 cups of the flour, 1/3 cup granulated sugar, the salt and yeast with a wooden spoon until well mixed. In a 1-quart saucepan, heat the milk over medium heat until very warm and an instant-read thermometer reads 120°F to 130°F. Add the warm milk, 1/4 cup butter and egg to the flour mixture. Beat with an electric mixer on low speed 1 minute, stopping frequently to scrape batter from side and bottom of bowl with a rubber spatula, until flour mixture is moistened. Beat on medium speed 1 minute, stopping frequently to scrape bowl. With a wooden spoon, stir in enough of the remaining flour, about 1/2 cup at a time, until dough is soft, leaves side of bowl and is easy to handle (dough may be slightly sticky).