Ingredients for 14 servings:
1. 1 cup unsalted butter, softened
2. 3 cups sugar
3. 6 large eggs, separated
4. 3 cups flour
5. 1/4 teaspoon salt
6. 1/4 teaspoon baking soda
7. 8 ounces sour cream
8. 1 teaspoon vanilla extract
9. 2 teaspoons rum extract

Directions:
1. Preheat oven to 300. Grease tube pan with removable bottom. Add a ring of wax paper to bottom of pan to ease release after cooking.
2. Beat butter and sugar thoroughly. Add yolks.
3. In another bowl, combine flour, salt and baking soda.
4. Alternately add flour mixture and sour cream to butter mixture.
5. Add extracts and rum, if desired.
6. In separate chilled bowl, beat whites to stiff peaks.
7. Fold whites into batter.
8. Spoon into pan.
9. Coat top with additional sugar.
10. Bake at 300 for 1.5 to 2 hours until cake tester comes out clean.