Preheat the oven to 350°F and line a cupcake tray with liners.
Mix the dry ingredients together (flour, salt, baking powder, baking soda, cinnamon, and pumpkin pie spice) in a bowl and set aside.
1 ½ cups all-purpose flour, 1 tsp baking powder, ½ tsp baking soda, 1 tsp cinnamon, 2 tsp pumpkin pie spice, ½ tsp fine sea salt
In a large bowl, mix the granulated and brown sugars and the oil together with an electric beater or a whisk.
½ cup granulated sugar, ½ cup brown sugar, ½ cup vegetable oil
Mix in the pumpkin puree and then the sour cream.
1 cups pumpkin puree, ½ cups sour cream
Beat in the eggs, then the vanilla and the lemon juice.
2 eggs, 2 tsp vanilla, 1 tbsp lemon juice
Add the dry ingredients to the bowl with the sugars, oil, pumpkin, sour cream, eggs, and vanilla. Mix until combined, but be careful not to overmix or the cake will be gummy.
Fill each cupcake liner about ⅔ of the way full with batter (about 3 tbsp per liner).
Bake for 17-19 minutes, then let the cupcakes cool completely before frosting them.
For the frosting, mix the cream cheese, butter, vanilla, cinnamon, and sea salt with an electric beater until smooth.
8 oz cream cheese, ½ cup butter, 3 cups powdered sugar, 1 tsp cinnamon, 1 tsp vanilla, ¼ tsp salt
Frost the cupcakes using an offset spatula or a piping bag. Decorate with an extra dusting of cinnamon.