Preheat oven to 350 degrees. Line cupcake pan with cupcake liners. Set aside.

In a large bowl, whisk together flour, baking powder, ground cinnamon and nutmeg, baking soda, and salt. Set aside.

In another large bowl, whisk together pumpkin puree, sugars, vegetable oil, and eggs.

Add flour mixture to wet ingredients; mix just until combined.

Scoop batter into cupcake liners - no more than ⅔ full, or use a #24 disher to scoop batter. Bake for 12-15 minutes. Insert a toothpick into the center of the cupcake, if it comes out clean it is done. Remove cupcakes from oven and allow cupcakes to cool in cupcake pan for 3 minutes; transfer to wire rack and cool completely. Cupcakes should be cooled completely before frosting.

In a large bowl using an electric mixer, cream butter and shortening until creamy and smooth. Add salt and water; mix until combined.

Turn mixer on lowest speed and slowly add 1 lb of powdered sugar; mix until creamy. Scrape down bowl as necessary.

Turn mixer on medium speed for 1 minute. Turn mixer to slowest speed. Slowly add remaining 2 lbs powdered sugar and clear vanilla extract. Blend until creamy.

Add ground cinnamon to buttercream; mix on high speed for 4 minutes, or until fluffy.

Pipe using your favorite decorating tip or frost with a spatula onto cooled cupcakes. Top with Royal Icing Pumpkins. Eat & Enjoy!