Pumpkin Chocolate Chip Cookies

1/2 cup butter
1 1/2 cups sugar
1 egg
1 cup canned pumpkin puree
1 tsp vanilla
2 1/2 cups flour
1 tsp baking soda
1 tsp baking powder
1 tsp cinnamon
1/2 tsp nutmeg
1/2 tsp salt
2 cups chocolate chips
Using a mixer, beat together butter and sugar until fluffy.  Add egg and beat until smooth.  Add the pumpkin puree and vanilla.  Slowly add flour, baking soda, baking powder, cinnamon, nutmeg and salt.  Stir in chocolate chips.  Using cookie scoop, place 1 inch diameter cookie balls on parchment papers.  Bake at 350 degrees for 12 minutes or until edges are firm. 
2 cups powdered sugar
3 T milk
1 T melted butter
1 tsp vanilla
Beat until smooth.  Drizzle on cookies.