Preheat your oven to 350°F (175°C) and grease an 8x8-inch baking pan.
In a mixing bowl, combine flour, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger.
In a separate bowl, whisk pumpkin puree, granulated sugar, brown sugar, oil, eggs, and vanilla extract until smooth.
Gradually mix the wet ingredients into the dry mixture, stirring until just combined.
Pour the batter into the prepared baking pan, spreading it evenly.
For the streusel, combine brown sugar, flour, and cinnamon in a small bowl.
Cut in the cold butter until the mixture forms coarse crumbs.
Sprinkle the streusel over the batter in an even layer.
Bake for 40 minutes or until a toothpick inserted in the center comes out clean.
Cool for 10 minutes before slicing. Serve warm or at room temperature.