Step 1: Preheat your oven to 350°F (175°C). Grease two 8x4-inch loaf pans and line the bottoms with parchment paper, leaving an overhang on the long sides for easy removal.
Step 2: In a large bowl, whisk together the 2 cups all-purpose flour, baking soda, salt, 1 teaspoon ground cinnamon, nutmeg, ginger, cloves, and allspice until well combined.
Step 3: Stir in the granulated sugar and 1/2 cup packed light brown sugar into the dry mixture until evenly distributed.
Step 4: In a separate medium bowl, whisk together the canola oil, eggs, pumpkin puree, water, and vanilla extract until smooth.
Step 5: Pour the wet ingredients into the dry ingredients. Mix with a spatula or wooden spoon just until no streaks of flour remain. Be careful not to overmix.
Step 6: In a small bowl, prepare the crumb topping: combine the 1/2 cup all-purpose flour, 1/4 cup packed light brown sugar, and 1/2 teaspoon ground cinnamon. Add the diced cold butter and cut it into the dry ingredients using a pastry blender or your fingertips until the mixture resembles coarse crumbs.
Step 7: Divide the pumpkin bread batter evenly between the two prepared loaf pans, smoothing the tops with a spatula.
Step 8: Evenly sprinkle the crumb topping over the batter in both pans.
Step 9: Bake for 55-65 minutes, or until a wooden skewer or toothpick inserted into the center of a loaf comes out clean. If the topping starts to brown too quickly, you can lightly tent the loaves with aluminum foil.
Step 10: Let the pumpkin bread cool in the pans for 10-15 minutes before carefully lifting them out using the parchment paper overhang. Transfer to a wire rack to cool completely before slicing and serving.