Stir together the flours, oats, baking powder, baking soda, cinnamon, and salt.
In a large bowl, beat the eggs. Gradually beat in the brown sugar until the mixture is thick. Beat in the melted butter or margarine and the vanilla. Beat flour mixture into the liquid mixture, and then stir in the grated pears. Turn the batter into a greased and floured tube pan.
Bake at 325 degrees F (165 degrees C) for 70 minutes, or until it tests done with a toothpick. Transfer cake to a rack to cool.