Min the filling ingredients in small bowl and set aside. In large bowl beat butter and sugar, until light beat in egg yolks, oil, applesauce and vanilla...combine the dry ingredients add to sugar mixture alternately with sour cream. In another bowl, with clean beaters beat on high speed the egg whites until stiff peaks form. fold into batter.
Pour half the batter into a 10 inch fluted tube pan which has been coated with nonstick cooking spray and lightly flouredadd the nut mixture and top with remaining batter,,,Bake in 350F oven for 45 to 55 minutes or until toothpick inserted in center comes out clean..Remove from oven cool in pan 10 minutes and remove to wire rack to cool...sprinkle with the confectioners sugar..serve plain or with a dollop of ice cream.