I do my best to keep up with the kids, to stay in the know about what's new. I caught wind of the microbrew trend a couple years back, and I even went so far as to buy a beer-of-the-month club subscription for D. (She loved it so much, she told me to never think again about birthday presents: it's beer club from here on out.) But every so often, a new tidbit of knowledge seems to sweep the food world by storm while skipping me completely, Passover-style. This time, it was tapioca flour, which has quickly supplanted corn starch as the best thickener, ever. Unlike corn starch, tapioca is undetectable in every way. It thickens up pies without any of that milky, gloopy, corn starch texture. It also doesn't threaten to leave a raw-flour taste if it doesn't cook completely. In short, it's basically foolproof. Cook a pie with tapioca, and you'll think there's no thickener in it at all - until you cut the first slice and see that there is no puddle of murky fruit liquid swamping your pie. It's an amazing feat. Your guests will ooh and ahh.
So how did I miss the trend? I don't know. But I blame being late to the tapioca party for not sharing this amazing pie recipe until now. This, my friends, is the best blackberry pie. Ever.
Blackberries are in season right now. If you haven't had any over the past couple of weeks, carpe diem, people. They're tangy, sweet, and complex. They pair well with cinnamon and lemon, both of which are in this pie recipe. Oh, and butter. They go well with butter. We've got that here, too.
If you've been following along, I recently settled on my ideal pie crust recipe. I used that here, and it's as good as I remember. But I'm also a sucker for a good crumb topping, and I usually find double crust pies to be a little too crusty. For this pie, I riffed on Deb's crumb topping for sour cherry pie, which calls for ground almonds and ground oats. It's got great flavor, and it pairs perfectly with blackberries. If you don't have oats or oat flour, you can substitute whole wheat or even white flour here.
We had plenty of blackberries for this pie, and Elise's pie filling fit the bill just perfectly with only minor tweaks. If you'd like to mix blackberries with another summer berry, this pie is a great place to do that. Also, if you're not a cinnamon person (strange, I know, but there are such people), omit. And if you're the type who loves orange zest, blackberries, cinnamon, and orange are a trio made in heaven. Do it.
Once you've made a pie with tapioca flour, you may never go back. And you know what? It's pretty good on this side of things.
1 recipe best all-butter pie crust
For the pie filling: 5-6 cups blackberries, rinsed, picked clean, and patted dry (if using frozen berries, defrost fully and drain) 1/2 cup sugar 1 teaspoon lemon juice 1 teaspoon lemon zest 1/2 teaspoon cinnamon 1/4 teaspoon vanilla extract 1/4 teaspoon almond extract (optional, but it plays off the almond crumble really nicely) 3 Tbsp tapioca flour (I found it in the baking aisle of a natural foods store; Whole Foods and many supermarkets carry it, too)
For the topping: 2/3 cup whole oats, ground to a flour in a food processor (or, if you have it, 1/2 cup oat flour) 1/2 cup all-purpose flour 1/2 cup sugar 1/4 teaspoon ground cinnamon 1/2 teaspoon kosher salt (you might want to first read up on kosher salts) 3/4 cup unsalted whole almonds, coarsely ground in a food processor (or, if you have it, 1/2 cup almond meal) 6 tablespoons unsalted butter, melted and cooled
Prepare the crust: Preheat the oven to 400 degrees. Roll out the chilled pie dough into a 12-inch disk. Gently lower into a 9- or 9.5-inch pie dish. (I do this by gently folding the dough into quarters, lifting it into the dish, and then gently unfolding it, as pictured above.) Trim the edges of the crust, leaving a 1/2-inch overhang. Crimp the edges, line with foil or wax paper, fill with pie weights or rice/beans, and bake for 30 minutes, until lightly browned. Remove pie crust from the oven, remove weights and lining, and allow to cool completely. Meanwhile...
Prepare the filling: Put blackberries, sugar, lemon juice and zest, cinnamon, extracts, and tapioca flour into a large bowl. Toss gently to coat berries evenly, and leave to macerate for 20 minutes. While this is macerating...
Prepare the crumb topping: Combine flours, sugar, cinnamon, salt, and almond meal in a medium bowl. Add melted butter and stir until mixture resembles wet sand.
Make the pie: Spoon blackberries into bottom crust. Sprinkle crumb topping evenly over the top of the pie. Set the pie on a baking sheet (to catch any juices that drip, avoiding that whole smoking oven thing), and bake for 30 minutes. Reduce heat to 350 degrees, and bake another 30-35 minutes, until juices are bubbling and crumb topping is browned. Let cool at least 30 minutes before eating.
Serve with vanilla ice cream, FTW.