Brush both sides of bread with butter; place in a greased 13x9-in. baking dish. In a large bowl, beat eggs and yolks. Add milk, cream, sugar, vanilla and nutmeg; mix well. Pour over the bread slices. Cover and chill overnight. Remove from the refrigerator 30 minutes before baking. , Bake, uncovered, at 350° for 55-60 minutes or until a knife inserted in the center comes out clean. Cool 10 minutes before serving. Dust with confectioners' sugar if desired.