Grease and flour a Bundt cake pan or tube cake pan. Heat oven to 325°F.
Cream sugars and butter until light and fluffy. Beat in eggs, one at a time, beating well after each addition. Beat in vanilla. Sift together the cake flour and salt. In a cup, combine the sour cream and baking soda. Blend dry ingredients into the creamed mixture a little at a time, alternating additions with the sour cream and baking soda mixture, ending with the flour mixture.
Spoon the batter into the prepared baking pan. Bake for 1 hour and 20 minutes, or until a cake tester or wooden pick comes out clean when inserted in the center of the cake. Cool in pan or rack for 10 minutes. Invert onto a serving plate and cool completely. Drizzle with a glaze or dust with powdered sugar.