Beat first 4 ingredients at medium speed with an electric mixer until smooth.
Combine flour and next 5 ingredients; add to sugar mixture alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Stir in walnuts and dates. Pour into a greased and floured 12-cup Bundt pan.
Bake at 350° for 1 hour and 10 minutes or until a wooden pick inserted in center comes out clean. Place on a wire rack. Pierce cake halfway through at 1-inch intervals with a long wooden pick. Pour half of syrup over cake. Cool in pan on wire rack 15 minutes. Invert onto plate; pierce top and sides with long pick. Pour remaining syrup over cake; brush onto sides until absorbed.
