Combine the melted butter, granulated sugar, brown sugar, pumpkin spice, cinnamon and salt in a bowl until combined. Add the flour and stir with a wooden spoon or stiff spatula until the mixture forms a cohesive dough. Set aside and cool completely, about 15 - 20 minutes.

In a medium bowl whisk together the flour, pumpkin spice, cinnamon, baking powder, baking soda and salt. Set aside.

In a large mixing bowl combine the butter, oil, granulated sugar and brown sugar. Using an electric mixer blend on medium speed until lightened and creamy, about 3 minutes. Add the eggs and mix on low until incorporated. Add the pumpkin puree, vanilla and half the flour mixture. Mix on low until all ingredients are incorporated. Pour in the remaining flour and blend again to combine. Scrape down the sides and bottom of the bowl with a spatula and beat on high for 2 minutes.

Pour the batter into the prepared pan and spread evenly. Using your hands, squeeze together clumps of the crumb topping. Pinch off large pea size pieces and spread in an even layer over the batter starting around the edges working toward the center until all crumb-topping is distributed.

Bake until the crumbs are golden brown and a toothpick inserted in the center comes out clean, about 45 minutes.

Cool for 30 minutes before serving. Crumb cake can be served warm, cold or room temperature. Top with whipped cream, ice cream or a sprinkle of powdered sugar as desired.