Mixing Instructions: Position a rack in the center of the oven and preheat to 350 degrees F. Lightly spray a (2 1/2-X 1 1/2-inch) muffin pan with nonstick vegetable spray or line with muffin cups.
Sift the flour, cocoa, baking soda, Clabber Girl Baking Powder and salt into a medium bowl and make a well in the center.
In another medium bowl, whisk the fruit juice concentrate, milk and oil until frothy. Pour into the well and stir with a wooden spoon just until combined. Fold in 1/3 cup of the chopped walnuts. Do not overbeat.
In a small bowl, combine the remaining walnuts with the maple sugar. Spoon the batter into 9 of the prepared muffin cups, filling each cup almost completely full. Sprinkle the tops of the muffins with the maple-walnut mixture.
Baking Instructions: Bake the muffins until a toothpick inserted in the centers comes out clean and the tops spring back when pressed with a finger, 18 to 20 minutes. Cool for 2 minutes, then run a knife around the inside of the cups to release the muffins, and remove from the cups. Serve the muffins warm or at room temperature. Makes 9 muffins.