1. In a bowl, with an electric mixer on medium speed, beat oil, sugar, eggs, 1/3 cup honey, and 1 1/2 teaspoons orange peel until smooth and well blended.
2. In another bowl, mix all-purpose and whole-wheat flours, baking powder, salt, and sesame seeds; stir or beat into oil mixture until well blended. Spread batter evenly in a lightly oiled 9- by 13-inch baking pan.
3. Bake in a 375° oven until center springs back when lightly touched and top is richly browned, 18 to 20 minutes.
4. Meanwhile, in a bowl, mix melted butter, remaining 1/2 cup honey, and remaining 1 1/2 teaspoons grated orange peel until smooth. With a wooden skewer, pierce warm baked bar at 1/2-inch intervals. Pour honey mixture evenly over the top.
5. Let cool at least 10 minutes, then cut into 24 bars. Let cool completely.
Note: Nutritional analysis is per bar.