Italian Prune Butter

Remember those prunes I got?
Yeah, I made prune butter as soon as the crock pot was clean and I was awake. 
Here's the source: Eating Small Potatoes.
Here's what I used:
1 1/4 lb prunes (18 prunes)
Just about 3 oz sugar (approx 1/3 c)
1/4 tsp vanilla (actually about 1/3, but that measure doesn't exist, so I stuck with 1/4)
Here's the broken down ratio:
About 1/4 c sugar to 1 lb fruit, and 1/4 tsp vanilla per lb.

First, wash your prunes, halve, and pit them. Cut them into a bowl on a scale because you want to know how many prunes you used. End up counting the pits anyway.

Prunes halved and mostly pitted. They come out of the mix pretty easily if you can't get them out of the fruit itself.

 Second, work out the ratio of sugar from the website you found this recipe on. Decide that you'll use your scale to add sugar and not worry about tricky conversions between ounces and cups and pounds.
Add however much sugar you need. If you're using this website, put in 1/4 c sugar for each pound of prunes.

Prunes and about 3 oz sugar.

 Dump the mixture into the crock pot. Admire, and worry that the sugar will burn. Stir obsessively.

Prunes and sugar in the crock pot. I was very anal about taking lots of pictures.

 The prunes will start making their own juice pretty much as soon as they get warm.  Feel relief, but still stir way too often.

The sugar has started to draw the juices out of the prunes.

 Become slightly enraged by the site of the crock pot with its lid on. Feel a deep, pressing need to remove it and observe its contents.
Resist this urge by going for a walk and then doing your housemate's workout DVD.

This is the most maddening sight in the world. All I want to do is take off the lid and stir.

 Dance around the pot whenever you're not doing something else.
This is about a third of the way done. The skins are starting to come off and disintegrate, and the flesh is getting all smooshy.
NB: the flash on my camera was being dumb and made everything look much redder in the pot than it should have been. The flesh was a light yellow for most of the time while the juices were a purply brown that was pretty hard to distinguish from the black crock pot.

They're starting to stew in their own juices and make my pictures look funny.

 This is about half done. The flesh has almost formed a smooshy mass with some skins floating around and some juices still around the edges. By the end, you want those skins to be all the way dissolved into the smooshy stuff and no juice around the edge.

The fruits are all the way smooshified, with just some skins floating around.

 This is where I realized that I should probably have started this last night or woken up earlier. I don't have enough prunes to make a nice, thermally-stable butter that can sit in the crock pot overnight and not burn. I was thinking I would just set it to warm and deal with it in my mid-morning "lunch" break, but then I realized that I liked the taste and texture already.

This is more what the prunes looked like the whole time; but don't be turned off by the brown color. They are delicious.

 I added vanilla here. It adds a nice complexity to the flavor. I wouldn't recommend cinnamon, but if you have a thing for plummy things with a certain spice, go for it.
Then I let it sit for a few minutes and jarred it.

The finished plum butter, in the ubiquitous used jam jar.

The butter that I got is less buttery and more jammy, with some half-dissolved skins still in it. It's tart, sweet, and tangy, with enough body to be a delicious spread. The vanilla blends well, but would not be required. I'd say that I got about 1 1/2 cups of butter; it might have gone down to 1 or 1 1/4 by morning.

EDIT: As a side note, I've decided that I NEED a tiny crock pot when I get my own place. I want a little one about half the size of A's so I can make 1-person jams and applesauces and suchlike.