Spray a 9-inch springform pan with nonstick spray; set pan aside. In a medium bowl combine flour, baking powder, and baking soda; set aside.
In a large mixing bowl combine sugar, margarine, and vanilla. Beat with an electric mixer on medium speed until well combined. Add egg and egg white; beat 2 minutes at medium speed. Combine yogurt and milk. Add flour mixture alternately with yogurt mixture, beating at low speed just until mixed after each addition. Stir in apricots, prunes, and nuts. Spread batter in prepared pan. Place pan on baking sheet.
Bake in a 350 degree F oven for 40 to 45 minutes or until a wooden toothpick inserted near the center comes out clean. Cool cake in pan on a wire rack.
Meanwhile, for Orange-Honey Glaze, in a small saucepan combine 1/2 cup honey, shredded orange peel, and orange juice. Heat just to boiling, stirring occasionally. Remove from heat.
Pierce entire top surface of cake with a fork. Spoon warm Orange-Honey Glaze over cake. Cool for 30 minutes more. Remove sides of pan. Cool completely.
To serve, cut into wedges. Top each wedge with whipped topping, additional apricots and prunes, and orange peel, if desired. Makes 10 servings.