How to Make It
Preheat oven to 325°F. Coat a 9- x 5-inch loaf pan with cooking spray. Whisk together 1 1/4 cups all-purpose flour, whole-wheat flour, ground ginger, baking soda, cinnamon, salt, pepper, and cloves in a bowl. Whisk together molasses and boiling water in a second bowl.
Beat butter and brown sugar in a bowl with a mixer on medium-high speed until fluffy. Beat in egg and zest. With mixer running on low speed, add flour mixture alternately with molasses mixture. Stir together crystallized ginger and remaining 1 teaspoon flour; fold into batter. Pour batter into prepared pan.
Bake at 325°F until a wooden pick inserted in center comes out clean, about 55 minutes. Cool in pan on a wire rack.