Preheat your oven to 350°F (175°C). Grease and flour your 9x13 inch baking pan.
In a large mixing bowl, combine the flour, sugar, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt. Whisk until well blended.
In another mixing bowl, whisk together the pumpkin puree, vegetable oil, and eggs until smooth.
Gradually add the wet mixture to the dry ingredients, stirring with a rubber spatula until just combined. Be careful not to overmix.
Pour the batter into the prepared baking pan and smooth the top with the spatula.
Bake in the preheated oven for 30 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Once baked, remove the cake from the oven and allow it to cool in the pan for 10 minutes. Then transfer it to a cooling rack to cool completely.
While the cake is cooling, prepare the whipped cinnamon frosting. In a mixing bowl, combine the heavy whipping cream, powdered sugar, vanilla extract, and ground cinnamon.
Using a hand mixer or stand mixer, whip the mixture on medium-high speed until stiff peaks form.
Once the cake is completely cool, spread the whipped cinnamon frosting evenly over the top. If desired, use a piping bag for decorative touches.
Slice into squares and serve. Enjoy!