In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the pumpkin puree, egg, and vanilla extract until well combined.
In another bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Shape and Bake:
Scoop rounded tablespoons of dough and place them onto the prepared baking sheets. Flatten each cookie slightly with the back of a spoon.
Bake for 10-12 minutes, or until the edges are lightly golden. Allow cookies to cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.
Prepare the Icing:
In a bowl, whisk together the powdered sugar, milk, melted butter, and vanilla extract until smooth. If desired, add a few drops of food coloring to tint the icing.
Once cookies are completely cool, spread a thin layer of icing on top of each cookie.
Serve and Enjoy: