Preheat oven to 350 degrees and line cupcake pan with 12 liners.
Add the butter, oil, and milk into a large bowl and mix until smooth.
Add the brown sugar and mix again until smooth.
Add the vanilla extract and eggs to the batter and mix until smooth.
In a second medium sized bowl, combine the flour, baking powder, baking soda, cornstarch, cinnamon, nutmeg, ginger, cloves, and salt.
Add the dry ingredients from bowl two to the wet ingredients in bowl one and whisk until smooth again.
Gently fold in the pumpkin puree and chocolate chips.
Fill each cupcake liner ¾ full.
Bake the cupcakes in the preheated oven for 15-18 minutes, or until a toothpick inserted in the middle of the cupcake comes out clean and dry.
Remove the cupcakes from the oven and allow to completely cool.