Preheat oven to 350 degrees F (175 degrees C). Line muffin pan with 15 muffin liners.
In a medium bowl, whisk together All-Purpose Flour (1 3/4 cup), Baking Powder (1 1/4 teaspoon), Baking Soda (1 teaspoon), Salt (1/4 teaspoon), Ground Cinnamon (1 1/2 teaspoon), Ground Ginger (1/2 teaspoon), Ground Nutmeg (1/4 teaspoon), Ground Cloves (1/4 teaspoon), and Brown Sugar (1 1/4 cup) set aside.
In a large bowl, stir together Canned Pumpkin Purée (1 cup), Vegetable Oil (1/3 cup), Egg (2), and Milk (1/3 cup). Add the dry mixture to the wet mixture. Do this gradually, incorporating until no flour streaks remain. Don't over mix.
Spoon the batter evenly in all of the prepared muffin cups, filling each about 2/3 full (about 3 tablespoons of batter for each cupcake).
Bake for about 20 minutes and until a toothpick inserted into the center comes out clean.
Let cupcakes cool for 10 minutes, then transfer to a wire cooling rack. Let cupcakes cool completely before adding the frosting.
With an electric mixer, beat Unsalted Butter (3/4 cup) until fluffy, about 2 minutes.
Add the Cream Cheese (8 ounce), Vanilla Extract (1 1/2 teaspoon), and Ground Cinnamon (2 teaspoon) and continue to beat for another 2 minutes.
Turn the mixer down to a low speed and add in the Powdered Confectioners Sugar (3 cup) about 1 cup at a time. Mix until fully combined. Turn mixer back up to a higher speed and beat until fluffy, about 2 minutes.
Frost the cooled cupcakes using a flat knife or piping bag.
Cupcakes will keep well at room temperature for 4-6 hours. Refrigerate for up to 4 days.