Preheat oven to 350 degrees Fahrenheit.

Grease muffin tins or line with paper liners.

In a medium bowl, combine flour, pumpkin pie spice, baking soda, and salt.

Set aside the dry mixture.

In a large mixing bowl, combine pumpkin puree, eggs, sugar, water, and vegetable oil. Mix on low until just blended.

Add flour mixture to the wet ingredients and mix until just combined.

Spoon batter into prepared muffin tins until almost full.

Prepare the crumble topping by mixing brown sugar, sugar, pumpkin pie spice, and softened butter until crumbly.

Sprinkle crumble evenly over muffin batter.

Bake for 22-28 minutes or until a toothpick inserted in the center comes out clean.

Allow muffins to cool in the pan briefly, then transfer to wire racks to cool completely.