Preheat oven. Position a rack in the center of your oven and preheat to 425°F (218°C). Line a muffin pan with 5 paper liners, using every other well to space the muffins apart.
Mix wet ingredients. In a large bowl, whisk together the oil, pumpkin puree, egg, vanilla and milk until smooth. ¼ cup (60 ml) vegetable oil ¾ cup (170 g) pumpkin puree 1 large egg 2 Tablespoons (30 ml) milk ½ teaspoon vanilla extract
Add the sugars. Whisk in the granulated sugar and brown sugar until evenly combined. ¼ cup (50 g) granulated sugar ¼ cup (50 g) packed light brown sugar
Add remaining ingredients. Whisk in the baking soda, cinnamon, pumpkin pie spice, and salt until evenly combined. ½ teaspoon baking soda ¾ teaspoon ground cinnamon ¾ teaspoon pumpkin pie spice ¼ teaspoon salt
Add flour. Add the flour and whisk to combine. Be careful not to overmix. A few lumps may remain. ¾ cup + 2 Tablespoons (110 g) all-purpose flour
Fill muffin cups. Divide the batter evenly among the 5 prepared muffin cups, filling each to the top. Optional: Let rest for 15 minutes before baking for taller muffins. Sprinkle generously with turbinado sugar.
Bake. Bake for 5 minutes at 425°F (218°C). Without opening the oven door, reduce the temperature to 350°F (177°C) and continue baking for 15–18 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Cool. Allow the muffins to cool in the pan for 5 minutes before transferring to a wire rack.