Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.
In a medium bowl, whisk together the flour, baking soda, baking powder, cinnamon, nutmeg, and salt. Set aside.
In a large bowl, mix the pumpkin puree, granulated sugar, brown sugar, vegetable oil, 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, powdered sugar, and lemon juice until smooth.
Spoon half of the pumpkin batter into the prepared loaf pan, then dollop half of the cream cheese mixture on top. Use a butter knife to swirl it gently.
Add the remaining pumpkin batter on top of the cream cheese layer, followed by the remaining cream cheese mixture. Swirl again to create a marbled effect.
Bake in the preheated oven for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Let the bread cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.
Notes
Serve sliced with a dusting of powdered sugar on top, and add a small dollop of whipped cream or a scoop of vanilla ice cream on the side for an extra treat.