Preheat the oven to 350F. Line two muffin trays with paper liners.
Grate the zucchini and press between a clean kitchen towel or paper towels to extract excess water.
In a medium bowl, combine the all-purpose flour, baking soda, pumpkin pie spice, and salt. Set aside.
2½ cup all purpose flour, 1½ teaspoon baking soda, ½ teaspoon pumpkin pie spice, ½ teaspoon salt
In a mixing bowl, combine the grated zucchini, pumpkin purée, canola oil, brown sugar, granulated sugar, eggs, and vanilla extract.
2 cups grated zucchini, ¾ cup pumpkin purée, ⅓ cup canola oil, ½ cup brown sugar, ⅓ cup granulated sugar, 2 large eggs, 1 tablespoon vanilla extract
Mix the dry ingredients into the wet ingredients until just combined, scraping the sides and bottom of the bowl. Fill the muffin liners ¾ of the way.
Optional Crumble Topping: In a food processor pulse the butter, all purpose flour, granulated sugar, and pumpkin pie spice until in small crumbles. You can also use a pastry cutter if a food processor isn't available.
¼ cup butter, ¼ cup granulated sugar, ¼ cup all purpose flour, ½ teaspoon pumpkin pie spice