Preheat the oven to 350F and prepare your muffin pan.
In a large bowl, cream together butter and sugar until light and fluffy.
Add eggs, one at a time, followed by pumpkin. Blend until smooth.
In a separate bowl, whisk together buttermilk powder, flour, pumpkin pie spice, baking powder, baking soda, cinnamon, salt, and ginger until well combined.
Slowly combine dry mixture and creamed mixture, alternating with water and beating well after each addition.
Fill each muffin cup ¾ of the way full.
Bake for 20–25 minutes or until a toothpick comes out clean. Cool for 10 minutes prior to removing from the pan.
For the frosting, beat together cream cheese and butter until fluffy. Add powdered sugar, vanilla, and cinnamon. Beat until smooth.
Once the cupcakes have cooled completely, frost with cinnamon cream cheese frosting. Enjoy!