Preheat oven to 325. Spray loaf pans with non stick spray. In a mixer beat butter at medium speed until creamy. Gradually add both sugars, blending until fluffy. add eggs one at a time at low speed.
Stir buttermilk & baking soda together and set aside. Next mix flour and salt. Now add dry mixture alternately with wet, starting and finishing with dry mixture.
Beat at low speed until well blended, now add vanilla extract blend then pour evenly into loaf pans. Bake at 325 for 50-55 minutes or until loaf tests done in center. Cool 10 minutes then remove from pan and cool on rack. Serve or you can freeze up to 3 months.