Prep oven and pan. Position a rack in the center of the oven. Preheat oven to 350°F (177°C). Line a cupcake pan with 12 cupcake liners. Set aside.
Combine dry ingredients. In a medium bowl, whisk together the flour, pumpkin pie spice, salt, baking powder and baking soda together until combined. Set aside. 1 cup + 2 tablespoons (135 g) all purpose flour 1 tablespoon pumpkin pie spice ¼ teaspoon salt 1 ½ teaspoons baking powder ¼ teaspoon baking soda
Combine wet ingredients. In a large bowl, whisk together the granulated sugar, brown sugar, egg, oil, milk, pumpkin purée and vanilla together until combined. ½ cup (100 g) granulated sugar ¼ cup (53 g) packed light brown sugar 1 large egg ¼ cup (60 ml) neutral-tasting oil 6 Tablespoons (90 ml) milk 7 ½ ounces pumpkin puree 1 teaspoon vanilla extract
Combine wet and dry ingredients. Add the dry ingredients into the wet ingredients and stir until just combined. Do NOT overmix the batter.
Bake cupcakes. Spoon the batter evenly into 12 cups, filling each about 3/4 full. Bake in the preheated 350°F oven on the center rack for about 20 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and cool in the pan for five minutes then remove from the pan and allow to cool completely on a wire rack. Allow to cool completely before frosting.