In case you're not the most adventurous in the kitchen, this really isn't too difficult. You just throw all of the dry ingredients together in one bowl. Then combine all of the wet ingredients in another - I often use the pot that I've used to thaw some frozen pumpkin puree. Blend those wet ingredients. Add and blend in the dry ingredients. Pour into greased baking dish and bake. Done!
I usually make a double batch (all amounts doubled) and make three 9X13 glass dishes (just a little thinner that way) at one time - then there's plenty to take around for sharing.
You can just use a can of storebought pumpkin puree which is usually around 2 cups worth but we've been finding winter squash and pumpkins ridiculously cheap, and putting a pile in our living room fireplace for decoration. Then we "butcher" them one by one all winter. To do that, we cut one in half and scrape out the seeds and "guts". Then put the cleaned halves cut side up on a heavy baking sheet and cover the cut edges with foil so they don't get burnt. I've been leaving a big hole in the center so that the heat can get to that part better. I've been baking at 350 degrees for about 2 hours for the bigger sized squashes. Then you can just easily scoop out the softened flesh with a big spoon and throw out the skins. A food processor will then turn all that good stuff into smooth puree. I've used a blender in a pinch but then you might have to add some water to get it to work. The food processor really works best. The squash I used for the pictures was a sort of red, bumpy, round, hubbard type and was probably around 8 or 9 pounds, if I had to guess. I forgot to take its picture before it went under the knife. I didn't even scoop it real close to the skin and even so it still made a double batch (which used 4 cups of puree) and there was still enough for 4 sandwich bags (2 cups each) to go into the freezer for the next batches of cakes. And there was even still more puree that I put in the fridge for some experimental cooking (mwah hah hah) over the next couple of days.
Here's the pumpkin cake recipe followed by a bunch of pictures of the process that will hopefully encourage any apprehensive folks:
So first grease a baking dish (I smear it with butter):
Open a can of pumpkin or wizz up some baked flesh in the food processor:
Here are some extra bags of puree going into the freezer [aren't they pretty]:
The dry ingredients (flour, baking soda, salt and cinnamon):
The dry ingredients stirred:
The blended wet ingredients (pumpkin, sugar, molasses, oil and eggs):
The blended wet and dry ingredients:
Poured into the baking dish: