Preheat the oven to 350°F (175°C). Grease and flour a 12-cup muffin pan.
In a medium bowl, sift together the flour, baking powder, baking soda, ground ginger, and ground nutmeg. Set aside.
In the bowl of an electric mixer, cream together the butter and sugar until light and fluffy. Beat in the eggs, one at a time.
Mix in the pumpkin puree, sour cream, and vanilla extract.
Add the dry ingredients to the wet ingredients and mix until just combined.
Fold in the crystallized ginger and walnuts.
Divide the batter evenly among the prepared muffin tin cups, filling each cup about two-thirds full.
Bake for 25 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.
Allow the cupcakes to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
To make the frosting: In the bowl of an electric mixer, beat together the cream cheese and butter until light and fluffy. Beat in the powdered sugar and vanilla extract until smooth.
Frost the cooled cupcakes and enjoy!
Interesting Facts
Pumpkin puree is a great way to add moisture and flavor to baked goods.
Crystallized ginger adds a sweet and spicy flavor to the cupcakes.
Walnuts provide crunch and nutty flavor to the cupcakes.
Cream cheese frosting pairs perfectly with the pumpkin-ginger cupcakes.