Preheat the oven to 350°F. Grease two 9×5 inch loaf pans, or two 8×8 inch baking pans.
In a large bowl, mix together the flour, cinnamon, baking soda and salt.
In separate bowl, beat together the sugar, pumpkin, eggs, oil, apple sauce and water until fully combined.
Slowly mix in the dry ingredients to the wet ingredients until just combined. Fold in the diced apples. Pour the batter evenly into the prepared pans.
In a small bowl, mix together the streusel ingredients using a fork. Sprinkle the mixture evenly over each loaf.
Place the pans in the preheated oven. If you are using the 8×8 inch baking pans, bake for 50-55 minutes, and if using loaf pans, bake for 60-65 minutes, or until a toothpick inserted comes out clean.