Preheat the oven to 350F. Line 2 (12-cup) muffin pans with paper cupcake liners.

In a large bowl, sift together the flour, granulated sugar, baking powder, baking soda, salt, pumpkin pie spice, ginger, and cinnamon.

In another bowl, whisk together the pumpkin, oil, brown sugar, eggs, and vanilla. Add the pumpkin mixture to the flour mixture, and stir just until no streaks of flour remain.

Fill the paper liners three-quarters full with batter (about ¼ cup). If baking with one pan, cover the remaining batter in the bowl and set aside.

Bake for 20 minutes or until a toothpick inserted into the center comes out clean. If baking two pans at once, rotate the pans and swap oven racks after 12 minutes.

Let cool in the pan for 10 minutes. Remove and finish cooling on a wire rack.

In the bowl of a stand mixer fitted with the paddle attachment or a large mixing bowl, beat butter on medium speed until creamy, about 1 minute.

Add the cream cheese. Beat on medium speed until smooth, about 2 minutes, stopping to scrape down the sides of the bowl a few times.

Beat in the vanilla and salt just until combined.

Sift the powdered sugar into a large bowl.

With the mixer on low speed, slowly add the powdered sugar. When fully combined, increase the speed to medium and beat until light and fluffy, about 1 minute.

Place frosting in a piping bag fitted with a large closed star tip. Pipe over cooled cupcakes and decorate as desired.