Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan with cooking spray or butter.
In a large bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger.
In a separate bowl, mix together vegetable oil, granulated sugar, eggs, pumpkin puree, and milk until smooth.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Pour half of the batter into the prepared loaf pan. Sprinkle the brown sugar and 2 tablespoons of ground cinnamon evenly over the batter. Top with the remaining batter, smoothing the top.
Using a butter knife, gently swirl the cinnamon sugar layer into the batter to create a marbled effect.
Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean. Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.