Preheat your oven to 350°F (175°C). Lightly grease a 9x13 inch baking pan.
In a large bowl, whisk together the eggs, sugar, oil, and pumpkin until smooth.
Add flour, baking powder, baking soda, salt, and cinnamon. Stir until just combined.
Pour the batter into the prepared pan and smooth out the top.
Bake for 25–30 minutes, or until a toothpick comes out clean. Let cool completely before frosting.
To make the frosting: In another bowl, beat the cream cheese and butter together until creamy.
Add the powdered sugar and vanilla extract and beat until smooth.
Spread the frosting evenly over the cooled bars. Cut into squares and serve.