Preheat the oven to 350℉. Grease and parchment line your pan for easy removal and cutting later. If you don't want to line it, just grease the bottom and sides.
In a bowl, sift together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and cloves.
In the bowl of a stand mixer (or using a handheld mixer), cream together the butter, oil, and both sugars on medium speed for about 2 minutes.
Add the eggs one at a time, fully incorporating the first before adding the second. Once combined, add in the vanilla, pumpkin, and sour cream and mix on low speed until incorporated.
With the mixer running on low speed, add in the sifted dry ingredients and mix until just combined. Finish mixing in any flour on the sides of the bowl by hand.
Add the batter to the prepared baking pan and gently smooth out the top. Fluff the streusel with a fork, then spread it onto the top of the batter and gently press it down a bit.
Bake for 35-45 minutes, or until a toothpick inserted into the center of the cake comes out with no wet batter. Cool for about 30 minutes on a wire rack.