01 - Preheat oven to 350°F. Lightly grease a 13x9-inch sheet pan and line with parchment paper for easier removal.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, nutmeg, cloves, and ginger until well blended.
03 - In a large bowl, beat together granulated sugar, vegetable oil, eggs, pumpkin puree, and vanilla extract until mixture is smooth and homogeneous.
04 - Gradually fold the dry ingredients into the pumpkin mixture, stirring just until combined. Avoid overmixing the batter.
05 - Spread half of the pumpkin batter evenly into the prepared pan, smoothing the surface.
06 - In a separate bowl, beat softened cream cheese, granulated sugar, egg, and vanilla extract until smooth and creamy.
07 - Carefully spread the cream cheese layer over the pumpkin batter in the pan. Spoon the remaining pumpkin batter over the top and gently smooth.
08 - If using, evenly sprinkle with chopped pecans or walnuts and brown sugar.
09 - Bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean and the cake edges pull away from the pan.
10 - Allow cake to cool completely in the pan before slicing and serving.