Set your oven to 325°F (163°C). Grease a 9x13-inch metal pan with non-stick spray, line the bottom with parchment paper, and spray again. Use metal binder clips to hold down the parchment paper if necessary, but make sure to use metal clips, not plastic. Set the pan aside.
In a medium bowl, whisk together the flour, baking powder, cardamom, cinnamon, ginger, nutmeg, and salt. Set aside.
In a stand mixer with the paddle attachment, cream the sugar and eggs at medium speed until light and fluffy, about 4 minutes.
Add the oil and vanilla extract, beating at medium speed for about 30 seconds until fully combined. Then, add the pumpkin puree and mix until smooth, another 30 seconds.
With the mixer at low speed, slowly add the dry ingredient mixture into the wet ingredients, mixing until just combined.
Evenly spread the pumpkin batter into the prepared pan. Use the back of a spoon to smooth the top.
Bake for 30-35 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs.
Let the cake cool completely in the pan before frosting.