This cake is delicious served for breakfast or brunch.

1 1/2 c. sour cream
1 1/2 tbsp. baking soda
2 sticks butter
4 eggs, separated
2 c. sugar
3 c. flour
1/2 tsp. salt
2 tsp. baking powder
2 tsp. vanilla
1/2 c. brown sugar
1 tsp. cinnamon
1/2 c. grated walnuts

Mix sour cream with baking soda and set aside. Cream butter and egg yolks; add sugar until creamy. Sift together flour, salt and baking powder; alternate dry mixture and sour cream mixture into butter mixture. Add vanilla. Beat egg whites and fold into batter. Mix together remaining ingredients and sprinkle on top of batter. Cut through batter with a knife. Put into greased and floured tube pan. Bake at 350 degrees for 40 minutes (cake should spring back at touch). Sprinkle powdered sugar over top, if desired.