Pumpkin Spice Sugar Cookies with Cinnamon Frosting

These are really good but the cookie part came out pretty thick as you can see in the picture. It was much more cake like than cookie like. I think next time I might try just halving the recipe and seeing if I get a thinner cookie layer.
Also, the original recipe for the frosting just included a small amount of cinnamon. It didn't have a strong enough taste for my liking so I altered it a little.

Pumpkin Spice Sugar Cookies with Cinnamon Frosting

For the bars:
1 cup butter; room temperature
1/2 cup brown sugar
1 1/2 cup granulated sugar
4 eggs
2 tsp vanilla
1 cup pumpkin
6 cups flour
1 tsp salt
1/2 tsp baking soda
4 teaspoons pumpkin pie spice
1/4 teaspoon cardamom
1/4 teaspoon ground cloves

For the frosting:
1/2 cup butter; room temperature
1/2 cup shortening
1 tsp vanilla
pinch of salt
1/4 - 1/2 teaspoon ground cinnamon
4 cups powdered sugar
5 Tbsp milk
food coloring (if desired)

For the bars:
Cream butter and sugar until fluffy. Add the eggs, one at a time, mixing after each egg. Add vanilla and mix well. In a separate bowl combine flour, salt, baking soda, pumpkin pie spice, cardamom, and cloves. Stir the flour mixture with a whisk to combine. Add half of the flour mixture to the wet mixture and mix just until combined. Then add the pumpkin puree, followed by the remaining flour mixture. Stir until just combined. Spread on a greased 13x18 inch baking pan.

Bake at 375 degrees for 10-20 min, until light golden brown or until a toothpick comes out clean. Cool completely and frost. (I had to cook these for at least 20 minutes but each oven is different, so check at 10 minutes then every couple minutes after that until they are slightly brown around the edges.)

For the frosting:
Combine butter and shortening until smooth and creamy. Add vanilla and salt. Add powdered sugar in 1-2 cup increments alternately with milk until smooth and spreading consistency. Mix in cinnamon (and other spices if using) and mix until combined. Spread over cooled cookies.

*I added about 3/4 tsp cinnamon, 1/2 nutmeg, and 1/4 cloves to the frosting for a stronger spice flavor. 

Tip: To make your own Pumpkin Pie Spice, combine 1 teaspoon cinnamon, 1/2 teaspoon ginger, 1/4 teaspoon allspice, and 1/8 teaspoon nutmeg. Makes 2 teaspoons.