• Start by preheating the oven to 350 degrees. 
• Place liners in the cupcake pan, set aside
• Blend together the softened butter and the granulated sugar in a bowl using a stand or hand mixer until it is blended and fluffy looking.
• Add in the pumpkin spice, salt, baking powder, vanilla, milk, oil, pumpkin puree and egg whites. Blend until well combined.
• Add in the all purpose flour and mix very well. Stop the mixer and scrape down the sides when needed and mix again. Blend until smooth. The mixture should not contain any bumps or lumps. 
• Scoop out enough batter to fill each cupcake cavity about ⅔-¾ full. The batter will rise slightly during bake time.
• Bake in the oven for 14-16 minutes or until set and edges are just slightly browned.
• Allow to cool completely before attempting to remove the cupcakes from the pan. (about 20-30 minutes)

To make the Frosting:

• Blend together the softened butter and cream cheese in a bowl using a stand or hand mixer. 
• Add in the vanilla and salt. Finally add in the powdered sugar and mix until smooth. The mixture should be stiff peak consistency and creamy. 
• Divide the frosting between two bowls - about ¾ of it will be tinted orange and the remaining ¼ can be tinted green.
• Transfer the orange frosting to a piping bag fitted with a large round tip. Starting on the outside of the cupcakes, follow the curve of the cupcake and pipe a line down each side. Moving inward, pipe another line following the curve of the cupcake, just to the inside of the first lines. Finally, pipe the last line of frosting right down the middle - see photos as an example.
• Transfer the green frosting to a piping bag fitted with a leaf tip, if using. Pipe a few leaves around the top of the cupcake. Transfer the remaining green frosting to another piping bag (or ziploc) and cut a small hole in the tip. Pipe a small strand or vine around the leaves on each cupcake.