In a large mixing bowl, beat butter with sugars. Add pumpkin and mix until fully combined. Add cinnamon, nutmeg, salt, baking powder, baking soda, oats and flour. Mix until blended.
Fold in white chocolate morsels.
Drop cookies by large tablespoon onto a parchment paper lined cookie sheet. Bake in a preheated 350 degree F oven for 14-16 minutes. Remove and cool completely before glazing.
For the glaze, whisk together all the ingredients. Drizzle or spoon onto each cookie. Allow to set, about 15 minutes.
Notes
Storage Tips: Keep cookies in airtight container for up to one week. Or freeze for up to 3 months. Thaw in refrigerator and enjoy.