Preheat your oven to 350°F (175°C). Grease a 9-inch square or round baking pan with cooking spray or butter.

In a large mixing bowl, whisk together the flour, baking powder, cinnamon, nutmeg, ginger, and salt until blended.

In a separate bowl, mix together the pumpkin puree, eggs, vegetable oil, granulated sugar, and brown sugar until smooth.

Gently fold the wet mixture into the dry ingredients using a spatula until no dry flour remains.

Carefully pour the batter into the prepared baking pan, spreading it evenly with a spatula.

In a medium bowl, combine the cold unsalted butter, flour, and sugar, working the butter into the mix until it resembles coarse crumbs.

Sprinkle the crumble mixture generously over the cake batter.

Place the pan into the preheated oven and bake for 30–35 minutes, checking for doneness with a toothpick.

Once done, remove from the oven and allow to cool in the pan on a wire rack for about 15 minutes.