Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking dish.
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.
In a large mixing bowl, beat the softened butter and sugar together until light and fluffy. This should take about 3-4 minutes.
Beat in the pumpkin puree, eggs, and vanilla extract until well combined.
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
In a separate bowl, beat the softened cream cheese with the powdered sugar until creamy and smooth.
Pour about half of the pumpkin batter into the prepared baking dish and spread evenly. Then, dollop the cream cheese mixture over the top. Using a knife, swirl the cream cheese filling into the pumpkin batter. Top with the remaining pumpkin batter.
If desired, sprinkle chopped pecans on top for added crunch.
Bake in the preheated oven for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for about 10 minutes before slicing into squares. Serve warm or at room temperature.