It's my own recipe. It's a little verbose because I don't use a recipe, per se, and trying to figure one out so someone else can cook it is a hard problem. My ex used to say that I cook like a witch; just throw stuff in a cauldron and poof! dinner comes out.
For example, I make pretty good pastry. But the notes I took a lot of years ago when I learned it from my mom look like they are in Klingon and written with lipstick, and the steps read like "put as much flour as looks right in that middle-sized red bowl" which does not translate to anyone else's kitchen too well. I'm trying to derive them as I cook and write them down in terms others can understand at the request of my kids but it's hard slogging.
Makes 2 deep-dish pies. Best served still warm from the oven, with a scoop of vanilla ice cream.
This is not dietetic in any fashion whatsoever. If you're on a diet, there are some great recipes out there for sugar free or lower fat options. This is not one of them.
Step 1: Move to Western Washington
These things grow all up and down the Northwest. You want to end up where the word "blackberry" is usually preceded by a swear word, because that means the speaker has met them in the wild.
Step 2: Pick berries
When it comes to this step, it helps if you keep the mantra "If you're not miserable, you're doing it wrong!" ;)
Watch the banks of blackberry bushes that line many streets as you drive by, or when you're walking around your neighborhood. In April or May they'll have clusters of light pink flowers all over them. The time they're ripe varies dramatically based on the spring and early summer weather. Unless my luck has changed, it's been my experience they come ripe during the hottest, stickiest part of August.
The berries are hanging in clusters under the leaves. The last berry on the tip of the cluster comes ripe first, and is always the biggest and the sweetest. Then the others around it come ripe. I like the second crop for jam because they're firmer and their stronger juice stands up to the recipes better.
What you may not have realized if you really did just move here and were taking your cues from your car as you whizzed by is that the berries hang off a vine that makes the briers that locked away Sleeping Beauty seem like frail saplings. A mature Himalayan blackberry vine averages an inch thick, and is armed with hooked spikes. I've seen them bigger than my two thumbs together with 1/2" thorns. Even the first year seedlings come out of the ground coated in fine needles. The best berries grow one layer in on the second year growth, where they get sun but are partially shaded by the new growth out on the edges. That means in order to get them, you have to reach between the vines as far as you can.
I mentioned the thorns, right? Yeah. You're going to get scratch and snagged all over. Long sleeves are a must and long pants to protect your legs as you lean in. I tried wearing fingerless gloves once just to try to make things a little easier, but they got in the way too much. YMMV on that. A cane or hooked stick to pull vines closer to you might also be helpful.
To make matters more interesting, the way the vines creep across the ground devouring all in their path means your average bank of vines has all sorts of other things growing through it, and some of them are just as mean as their camouflage. I ran into one memorable patch several years ago that had some really glorious berries in it, but was also entwined with stinging nettles. I didn't realize it because I'd never met nettles. I was new to the area and I'd always kind of written them off as a bard's device. The thorns were scratching me, too, which masked their stings until I was way too far gone. I had a miserable couple days after that.
That's not to mention the wildlife. Those thorns make even the hardiest predator think twice, so you will find all sorts of birds, rabbits, rodents, grass snakes, etc live in there. The vines are fine with this - this helps them spread their seeds. There are bugs galore - this place is a spider's paradise.
If you are lucky, you find a bank with just morning glory vines tangled in it and just a few spider webs and aphids to work around. Try for the shady side of the road, with a decent path next to it so you're not wading in a swamp. Reminisce on the glorious pie you had last year while you're fishing around armpit-deep in Hell's thorny gullet. It will provide all the motivation you need.
How much to pick? It depends on what you're going to do with them. You need four cups of berries per pie, or eight cups for a single batch of jam. If you're freezing them for winter eating (there are few things more awesome than a hot blackberry cobbler on a nasty January day) then all bets are off and the question is how many can your freezer cope with. What I usually do is pick until about half an hour after the kids are bored/tired/sick of the heat and take them home and clean them (kids and berries). Then I just measure out what I need for the recipe and then freeze the remainder separately in a single layer on a cookie sheet. Once they're frozen, pour them into a freezer bag and you can use them just like you do the ones from the store.
Step 3: Cleaning
Once you're home, your work has just begun.
I block up the big sink and then pour the berries in. Fill the sink several inches deep in cold water and give the whole thing a good stir with your hands. Let the berries settle out for a minute. Now you have a floating layer of berry fuzz, berries that may not be completely ripe, and any random leaves/sticks/other-things-it-doesn't-bear-thinking-about. Pick the floating berries out of that, rinsing them in your hand before putting them in a colander to drain.
Once you've got all the floaty berries you want, skim off the stuff you don't and throw it away. Begin picking the berries out of the bottom of the sink by the small handful. Look through them, rinse them with the tap if you see anything. Then place them carefully in a colander set inside a bowl to drain.
Step 4: Crust
While berries are draining, prepare two deep-dish pie shells and enough other crust for a top. When I say prepare, I mean either a) take them out of the freezer where you put them when you got home from the store or b) make pie crust and dress your pans. I have had good results both ways and have no snobbishness against store-bought pastry. Marie Callender's makes a pretty good one that's easy to use, comes in good aluminum pans, and tastes good.
Step 5: Filling
Measure and sift into a big mixing bowl (Note: no plastic bowls unless you want it patchy purple colored from now on):
2 cups sugar
1/3 cup corn starch
1/3 cup flour
1/2 tsp (or a couple good shakes) ground cinnamon
The flour-and-cornstarch thing is at your discretion. I've found out that works best for me. You can use any proportion of those two ingredients (or even just one or the other). The sugar also gives lots of options. I've used Sugar in the Raw and regular granulated sugar. My mom uses some sugar substitute and it works the same.
Gently fold in eight cups of berries. Handle them with your hands as much as you can, and instead of stirring things, use a rubber spatula and lift the berries and sugar mix until they're coated. It will look dry but that's fine - it all comes together in the oven.
Gently divide the mixture between the two shells. Top with crust anyway you like, just make sure there's steam holes and you want a fairly high crimp on the edges to help keep any overflows in the pie.
Step 6: Bake
Put two pies on a cookie sheet, and place in the bottom of a 350 degree oven for 35 minutes. Watch for boil-overs. If the crust seems to be getting too brown (not likely the way my oven goes), cover the pointy bits with strips of tinfoil. You know your oven best.
At the end of 35 minutes take a look at the state of the crust. If it's getting too dark, cover the edges with foil. If not, turn the oven up to 400 degrees and let it go for another 10 minutes. Look again.