Preheating the oven to 350 degrees is required. Grease a baking tray with nonstick spray.
Combine the spices, baking powder, baking soda, and flour with a whisk in a small basin.
Cream together softened butter and sugar in a large mixing basin. Whisk in the egg, pumpkin, and vanilla. Lightly incorporate the dry ingredients to moisten.
Scoop dough into prepared pans using spoonfuls. Moisten slightly using a spoon or firm hand. Bake for 13 to 18 minutes at 350 degrees, or until set in the center.
After allowing the biscuits to completely cool, drizzle icing over the tops. To drizzle my icing, I prefer to use a zip lock bag with the corner snipped, but you can also use a spoon or utensil.
Whisk together all ingredients for the icing until homogeneous, adding milk as necessary to achieve the desired consistency.