Heat oven to 350°F. Spray bottom only of 9x5- or 8x4-inch loaf pan with cooking spray. In large bowl, mix sugar and butter; beat until light and fluffy. Beat in vanilla. Add buttermilk and eggs; blend well. (Mixture will appear curdled.)
In small bowl, mix remaining ingredients. Add to buttermilk mixture; stir just until dry ingredients are moistened. Pour batter into pan.
Bake 9x5-inch pan 50 to 65 minutes, 8x4-inch pan 55 to 75 minutes, or until toothpick inserted in center comes out clean. Loosen edges of bread; cool in pan on cooling rack 15 minutes. Remove bread from pan; place on cooling rack. Cool completely, about 1 1/2 hours. Wrap tightly, and store in refrigerator.