Preheat oven to 350 degrees.
Grease and flour 9x13 inch square or 2 (9 inch) round pans.
Beat butter, sugar, eggs, and vanilla until well blended. In seperate bowl combine ingerdients. Add alternately with water into butter mixture and mix together until smooth.
Pour batter into pans and bake 30-35 minutes or until toothpick inserted into center comes out clean.
Cool 10 minutes and remove to wire rack. Cool completely and frost.