Beat butter and cream cheese at medium speed with an electric mixer until creamy.
Gradually add sugar, beating well. Add eggs, 1 at a time. beating just until yellow disappears.
Combine flour and slat; gradually add to butter mixture, beating at low speed just until blended. After each addition. Stir in vanilla. Spoon batter into a greased and floured 10-inch Bundt or tube pan.
Bake at 300 degree for 1 hour and 35 minutes until a long wooden pick inserted in center comes out clean. Cool in pan on a wire rack 15 minutes, remove from pan, and cool completely on wire rack.