Preheat oven to 325°F. Grease and flour 9x5-inch loaf pan; set aside.
Beat butter, sugar and sour cream in large bowl with electric mixer on medium speed until light and fluffy. Add eggs, 1 at a time, beating well after each addition. Add Vanilla, Butter & Nut Flavor. Gradually beat in flour and baking soda on low speed until well mixed. Pour into prepared pan.
Bake 1 hour or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Remove from pan; cool completely on wire rack. Sprinkle with confectioners' sugar, if desired.