1 teaspoon vanilla
Cream butter and sugar well. Add one egg at a time, mixing well after each addition. Stir soda into sour cream, allowing it to dissolve. Add flour and sour cream to butter mixture. Add vanilla. Pour into a greased and floured tube or bundt pan. Bake at 300 degrees for 1 hour (place the cake in a cold oven, and then set the temperature. While baking, do not open oven). Continue baking at 325 degrees for 15 minutes longer. Cool on a rack for 10-15 minutes and remove to a plate or cooling rack.
My aunt and my mother have added their own variations to this recipe, including these tips:
Cream the butter, then add the sugar. My aunt also used 3 cups of sugar. She used the traditional method of adding the flour and sour cream alternately, beginning and ending with flour.