3 cups sugar
5 eggs, separated
1/2 tsp baking soda
1 cup buttermilk
3 cups all-purpose flour
1/2 tsp salt
1 Tbsp vanilla
Preheat oven to 325ºF. Grease and flour a 10-inch tube pan. In the bowl of an electric mixer, beat together the shortening and sugar until light and fluffy, approximately 5 minutes. Add egg yolks, beat to combine. Stir baking soda into buttermilk. Combine flour and salt. Add flour mixture and cream mixture to sugar mixture alternately beginning and ending with flour (1/3 flour mixture, 1/2 cream mixture, 1/3 flour mixture, 1/2 cream mixture, 1/3 flour mixture). Beat at slow speed after each addition. Stir in vanilla. In a separate bowl, beat the egg whites until stiff peaks form. Fold the egg whites not the batter. Pour batter into prepared pan. Bake for 60 to 70 minutes, or until a long wooden pick inserted in center comes out clean. Cool in pan on a wire rack for 10 minutes. Remove from pan and continue cooling on wire rack until completely cool.