Preheat the oven to 350℉. Line a 9X9-inch baking pan with parchment paper or spray with non-stick cooking spray.

In a mixing bowl using an electric mixer, cream together the softened butter, granulated sugar, and brown sugar until smooth. Add the eggs, vanilla, and pumpkin puree and continue creaming at high speed for 1 minute. The mixture might look grainy and separated at this step, but that is alright!

In a separate bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, ginger, and nutmeg. Add to the bowl of wet ingredients and mix at low speed just until no streaks of flour remain unmixed, being careful not to overmix.

Make the streusel by stirring together the melted butter, brown sugar, flour, cinnamon, and nutmeg into a crumbly mixture.

Assemble the cake, starting with a half of the batter spread into an even layer on the bottom of the prepared pan, followed by half of the streusel mixture, then drop spoonfuls of the remaining half of the batter before gently spreading it out. Lastly, sprinkle the remaining crumble on top of the second layer of batter.

Bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center comes out without any wet batter on it. Let cool for at least 15 minutes before serving.