Preheat oven to 350°F.
Beat butter and sugars in large bowl until creamy.
Beat in pumpkin, egg and vanilla until light and fluffy.
Mix in flour, cinnamon, baking powder, baking soda, salt and nutmeg until blended.
Lightly grease mini muffin tins and fill 3/4 full.
Bake 17-20 minutes or until set.
Cool 5 minutes in muffin tins and remove to wire racks. Cool completely.
In a large bowl, using an electric mixer on low speed, beat the butter, cream cheese, and vanilla until smooth and thoroughly blended, about 1 minute.
Add the powdered sugar, mixing until smooth, about 1 minute, then add the cinnamon and ginger and beat on medium speed for 1-2 minutes to lighten the frosting further.