Preheat your oven to 350°F and grease a 9x13 inch cake pan.

In a bowl, mix flour, both sugars, a pinch of salt, cinnamon, and pumpkin pie spice for the streusel topping; stir in melted butter until crumbly.

In a separate bowl, whisk together 2 cups flour, granulated sugar, baking powder, a pinch of baking soda, salt, and spices.

Cut in softened butter until the mix resembles coarse crumbs.

Stir half of the pumpkin puree into the dry mix until moistened.

Whisk the remaining pumpkin puree with eggs, a splash of oil, and vanilla until glossy and smooth.

Fold the wet pumpkin mixture into the dry batter until just blended.

Spread half the batter into the prepared pan. Sprinkle half the streusel over the batter.

Dollop the remaining batter on top, smooth it out, and finish with the rest of the streusel.

Bake for about 35 minutes until edges are golden.

If needed, add any reserved streusel and bake another 10-15 minutes until fully set.

Let cool slightly before serving.