Grease a 9x5x3-inch loaf pan with non-stick spray or butter to ensure the baked bread releases easily after baking.
In a medium bowl, vigorously whisk together the all-purpose flour, baking soda, salt, ground ginger, ground cinnamon, and ground nutmeg until everything is evenly combined. This helps distribute the leavening and spices uniformly.
In a separate large bowl, use a wooden spoon to mix together the pumpkin puree, melted and cooled unsalted butter, dark brown sugar, unsulphured molasses, minced candied or fresh ginger, beaten eggs, and water until just smooth. I like to use fresh ginger for an extra fragrant kick.
Add the dry ingredients from Step 2 into the wet ingredient mixture from Step 3. Stir gently with a wooden spoon or spatula just until everything is incorporated—do not overmix or the bread may turn out dense. Fold in the raisins if using.
Pour the batter into the prepared loaf pan. Bake at 350°F (175°C) for 50 to 60 minutes, or until a bamboo skewer inserted into the center comes out clean. I find that checking at the 50-minute mark is best, as ovens can vary.
Remove the loaf from the oven and let it cool in the pan for 10 minutes. Then, gently run a knife around the edge of the pan and invert the loaf onto a rack to fully cool before slicing. The flavor deepens as it rests—if you slice it while warm, use a bread knife as it may be more crumbly.