Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.

In a medium bowl, whisk together the flour, cinnamon, baking soda, salt, ginger, and nutmeg.

In a large bowl, beat together the pumpkin puree, granulated sugar, and brown sugar until well combined.

Add the vegetable oil, eggs, and vanilla extract to the pumpkin mixture and beat until smooth.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.

Pour the batter into the prepared baking pan and spread evenly.

Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.

Let the bars cool completely in the pan before frosting.

For the frosting, beat the softened cream cheese and butter in a large bowl until smooth.

Gradually beat in the sifted powdered sugar until smooth and creamy. Stir in the heavy cream and vanilla extract.

Spread the frosting evenly over the cooled pumpkin bars.

Cut into squares and serve.