Preheat oven to 375°.
Combine 1 tablespoon sugar, ground ginger, and cinnamon in a bowl. Stir well; set cinnamon mixture aside.
Place fresh ginger, 1/2 cup sugar, and lemon rind in a food processor; process until finely chopped. Set aside.
Combine remaining 7 tablespoons sugar, flour, baking soda, and salt in a large bowl; make a well in center of mixture. Combine the ginger mixture, buttermilk, prune butter, oil, egg, and egg white; stir with a whisk. Add to flour mixture, stirring just until moist.
Divide batter evenly among 12 muffin cups coated with cooking spray; sprinkle 1/4 teaspoon cinnamon mixture over each muffin. Bake at 375° for 20 minutes or until golden. Remove from pans immediately; let cool on a wire rack.