Preheat the oven to 350 degrees. In a medium bowl, combine the flours and baking powder. Set aside.

In a large bowl, combine the eggs, sugar, applesauce, oil, milk, extract, and lemon peel. Mix well. Slowly add the dry ingredients to the large bowl and mix well. Fold in the plums.

Pour the batter into a loaf pan that has been sprayed with nonstick cooking spray. Lay the plum slices on top. Bake for 40 to 45 minutes until a toothpick comes out clean. If necessary, cover the top loosely with foil so the plum slices do not overbake. Remove cake from oven and let cool for 10 minutes in the pan. Remove cake from pan and let cool completely.