In a large mixing bowl, whisk together the flour, baking soda, cinnamon, nutmeg and salt.
In the bowl of an electric mixer fitted with a paddle attachment, cream shortening, sugar, and pumpkin together. Add the egg and vanilla and mix well.
With the mixer on low, slowly add the dry ingredients. Blend only until smooth.
Drop by spoonfuls onto cookie sheet, the batter will be quite soft. Makes about 34 cookies.
Bake for 12-15 minutes and allow cookies to cool completely. Beat frosting ingredients until smooth and frost the cooled cookies.
Frosting
In a small saucepan, combine the brown sugar, butter over low heat, allowing the butter and sugar to melt. Whisk in the milk and stir until the mixture is runny and sugar has completely melted. Remove from heat and allow to cool somewhat.Whisk in powdered sugar until smooth. Then, working quickly before the frosting sets, spread about a teaspoon of icing over each cookie. Immediately garnish with chopped walnuts by pressing them into the top of the frosting while it is still warm.
If the icing sets and becomes less spreadable, heat gently for only about 30 seconds on the stove until the mixture becomes smooth again.
Recipe by Just a Smidgen at https://justasmidgen.com/2012/10/05/sugar-pie-pumpkins/