Generously greased & flour a 12-c Bundt pan or 10-inch tube pan.
In large bowl, combine flour, 2 cups sugar, salt, baking powder and club soda, buttermilk, 1 cup butter, 2 teaspoons vanilla and eggs; beat on low speed until moistened. Increase mixer speed to medium and beat for about 3 more minutes. Spoon batter to cake pan also spreading evenly.
Bake the cake in the preheated oven for 55 to 65 minutes, or until a toothpick inserted in the center comes out clean.
Meanwhile, in a small saucepan over low heat, combine the 3/4 cup sugar, 1/3 cup butter, 3 tablespoons water and 2 teaspoons vanilla; cook, stirring, until butter is melted. Do not bring blend to boil.
Remove the cake to a wire rack and, while still in the pan, pierce with a fork or skewer. Pour the hot butter sauce over the hot cake.