Instructions

1. Preheat your oven to 350 degrees. Line an 8×8 pan with parchment paper or aluminum foil, being sure to hang the edges over the top of the pan so you can easily lift it out of the pan after it is baked and cooled.
2. In a large bowl, whisk together the all-purpose flour, cinnamon, ginger, nutmeg, baking soda and salt.
3. In a medium bowl, combine the melted butter, brown sugar, egg, vanilla extract, and pumpkin puree until it is smooth and creamy.
4. Then, add the wet ingredients to the dry ingredients and combine using a rubber spatula until well combined and smooth. The mixture will be very thick.
5. Scoop the mixture into the prepared baking dish and spread into an even layer.
6. Bake for about 25 minutes, or until a toothpick comes out clean. Allow the bars to cool completely on a wire rack.
7. To make the frosting, toss the softened butter and brown sugar into the mixing bowl and mix until it is completely smooth and creamy.
8. Add the cinnamon, salt and sifted powdered sugar. Use the spatula to combine just a bit before you turn on the mixer to avoid a powdered sugar bomb in your kitchen.
9. Once your mixture is thoroughly combined, add vanilla extract and milk. I suggest starting with a tablespoon of milk and adding more if you want to be smoother. I added about 1-1/2 teaspoon and I think that was too much. The frosting was a bit droopy and after it was assembled, I wished it were thicker.
10. Once the cake is completely cooled you can spread the frosting to the top of the bars.
11. Cut into 9 bars and enjoy!