Preheat oven to 350º
In a smaller mixing bowl, combine flour, baking powder, cinnamon, cloves, ginger, and salt. Set aside
In a larger mixing bowl, cream butter and sugars together until fluffy
Add pumpkin puree, egg, and vanilla, and beat together until all is incorporated
Stir in dry ingredients until combined
Scoop into 1 ½ tablespoon sized balls and place on a baking sheet with a few inches of space between each for air flow
Flatten cookies to about ⅓ inch thick discs
Bake in center of oven for 10-12 minutes, until set
Remove from oven and transfer to wire rack to cool
While cookies are cooling, combine icing ingredients except for chocolate chips, and beat until smooth
Ice cooled cookies using a piping back or icing knife, and top with chocolate chips and cinnamon if desired.