Preheat the oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper or grease it well.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and cloves, and set aside.
In a large bowl, beat the granulated sugar, brown sugar, and oil until well combined, add the eggs one at a time, beating well after each addition, and stir in the pumpkin puree.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined, and do not overmix.
Pour the batter into the prepared pan and spread it evenly, then bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean, and allow the bars to cool completely in the pan.
In a medium bowl, beat the cream cheese and butter together until smooth, gradually add the powdered sugar one cup at a time, and mix until creamy, then stir in the vanilla extract.
Once the bars are completely cool, spread the cream cheese frosting evenly over the top.
Cut into squares and serve.