Preheat the oven to 350°F. Grease a 10x14 (jelly roll size) pan and set aside.
Crack eggs into a large bowl and beat. Add the pumpkin, neutral oil, white granulated sugar, brown sugar, and vanilla extract, whisking to incorporate.
1 15-oz can pumpkin puree, 3 large eggs, 1 cup neutral oil, 1 cup granulated sugar, ½ cup light brown sugar, 1 tsp vanilla extract
Mix in the flour, salt, baking soda, baking powder, and cinnamon. Whisk together until completely incorporated.
Pour into the greased pan and bake in the preheated 350°F oven for 20-30 minutes until a toothpick inserted in the middle comes out clean. Let cool completely before frosting.
To make the frosting, beat the room temperature butter and cream cheese until light and fluffy.
4 tbsp unsalted butter, 8 oz cream cheese
Add the vanilla extract and powdered sugar, adjusting the sugar to achieve the desired frosting consistency. Frost the cooled bars with the frosting.
½ tsp vanilla extract, 2 cups sifted powdered sugar
Video
Notes
Don't overmix the batter when adding in the dry ingredients. The flour begins to produce gluten, and if it gets overmixed, the bars will become tough.Use a skewer to test if the pumpkin bars are finished baking. Stick it near the center of the pan and remove it. If it comes out sticky with batter residue, then it requires more baking. If it is relatively clean, then the bars are finished baking.Push additional lumps of the powdered sugar through the sifter to add to the frosting. If there are lumps that are too difficult to push through, don't add to the frosting.