• Preheat your oven to 350°F and grease an 18 x 13-inch half-sheet pan.
• In a large mixing bowl, cream together the softened butter and sugar until well blended.
• Add the eggs, one at a time, mixing thoroughly after each addition. Then, fold in the canned pumpkin or squash.
• Gradually stir in the all-purpose flour, cinnamon, baking soda, baking powder, and salt until the batter is smooth and fully combined.
• Pour the mixture evenly into the prepared pan, smoothing out the top with a spatula.
• Bake for about 35 minutes, or until a toothpick inserted in the center comes out clean. Once baked, remove the pan from the oven and let the bars cool completely.

To Make Frosting:

• While the bars are cooling, beat together the softened cream cheese, butter, and vanilla extract in a medium-sized bowl until smooth and creamy.
• Gradually add the powdered sugar, mixing on low speed until incorporated. Then, increase the speed to whip the frosting until it becomes light and fluffy.
• Spread the frosting generously over the cooled bars. Optionally, sprinkle with a dusting of cinnamon for an extra touch of warmth.