Preheat oven to 350 degrees. Butter and lightly flour 2- 9 x 5 loaf pans or one pan and 9-10 muffin tins.
In a large bowl, sift together the flour, baking powder, baking soda, and salt. Sift the spices into the flour mixture- cinnamon through allspice. Set aside. In another bowl, combine the beaten eggs, sugar, oil, vanilla, pumpkin puree, and water. Gently whisk the wet ingredients into the dry until just incorporated taking care not to overmix.
Pour half the batter into the loaf pan. If desired, add raisins and pecans to the extra batter and pour into muffins tin or extra loaf pan. ***I find not everyone likes pecans and raisins so I omit them from the entire batter.*** In a third bowl, combine the streusel ingredients and with your fingers or a pastry cutter, mix until the mixture resembles coarse sand. Set aside.
Bake loaf for 30 minutes. Remove and add half the streusel topping to each loaf. Bake another 20-25 minutes or until a toothpick inserted in the center comes out clean. Let rest for 15 minutes before removing from the pan. For muffins- top muffins with streusel topping BEFORE baking. Bake muffins for 20 minutes or until a toothpick comes out clean.