Pound Cake

1 1/2 C softened butter
2 C white sugar
4 eggs
1 C sour cream
1/2 tsp baking powder
1 tsp vanilla
2 C cake flour

Generously grease and flour two 9" cake pans.  Cream butter and sugar.  Add eggs one at a time, beating until fluffy.  Add sour cream, baking powder and vanilla.  Mix well.  Add flour, one cup at a time.  Beat until batter is smooth.  Pour into pans and bake for 45-50 minutes.  Cool on wire rack for 20 minutes.  Loosen cakes and remove pans.  Leave on racks to cool completely.  When cake cools completely, wrap each in plastic wrap, be sure to seal tightly, then over wrap in foil.  Store in refrigerator for 48 hours.  Let set at room termpreture, wrapped, for 1 hour before serving.