Preheat oven to 350F. Line a muffin tin with 12 cupcake liners.

In a stand mixer fitted with a paddle attachment (or in a mixing bowl with an electric mixer), mix together brown sugar, sugar, and vegetable oil until combined well.

Add eggs, pumpkin puree, and vanilla extract, mixing to combine.

Add flour, baking powder, baking soda, cinnamon, nutmeg, ginger, cloves, and salt. Mix on low speed until incorporated, scraping down the sides of the bowl as needed.

Scoop batter into 12 muffin cups. Bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean. Allow to completely cool before frosting.

While the cupcakes cool, prepare the frosting. In a small saucepan over medium heat, whisk together flour and milk until no lumps remain.

Whisk continuously as it starts to thicken, then use a spatula or wooden spoon to continue stirring. Once the mixture is the consistency of pudding or school paste, remove from heat.

Allow the mixture to cool completely (you can transfer it to the fridge to cool if you're in a hurry. You don't want it to be warm at all or it will melt the butter).

Using an electric mixer, beat butter and sugar together until light and fluffy. Add in the cooled milk/four mixture and extract. Continue beating at high speed until it becomes light and fluffy, scraping down the sides of the bowl occasionally. The mixture will look strange at first, but just keep on beating it until it comes together--usually about 7-8 minutes.

When it's done, the frosting will be similar in texture to whipped cream, and the sugar will have dissolved (so it won't be grainy).

Frost cupcakes and serve.