Preheat the oven to 350 degrees F.
Grease and line two 9" cake pans with parchment paper.
In a medium bowl, combine the flour, baking powder, baking soda, salt, and pumpkin spice. Set aside.
In a separate large bowl, whisk together the brown sugar, granulated sugar, and oil.
Then, whisk in the eggs and vanilla, and lastly the pumpkin purée.
Add the dry ingredients to the wet and whisk until fully combined and smooth.
Pour the batter into the prepared pans and smooth out the top.
Bake the cake layers for about 20-25 minutes or until a toothpick inserted comes out clean and the cake starts pulling away from the sides of the pan.
Immediately turn the cakes out onto a wire rack to cool completely.