Preheat oven to 350 degrees F. Line an 8-inch metal pan with nonstick foil or grease and line with parchment.
Mix both flours, the brown sugar, baking powder and salt together in a mixing bowl and set aside.
In a second bowl, lightly whisk the egg, oil, honey and vanilla together. Add the egg mixture to the flour mixture and stir just until blended. Stir in the nuts, chocolate chips and white chips. Pour into the pan and spread to the edges
Bake on center rack for 18 to 20 minutes or until brown. Let cool completely. Cut into 16 squares
Notes
For best results, make sure not to use too much flour. Weigh it if you have a scale, or sift it if you don't. Also, when you stir the chips into the batter it may seem like there are too many. They tend to disperse when baked, so don't worry. You may even want more chips.