Best Blackberry Pie

Having done some experiments on whether cornstarch or tapioca was the best binder in a berry pie, then stumbling upon this recipe from Epicurious, I now have an answer. BOTH! I do still, however, use my own custom crust recipe whenever making pies or tarts. It's buttery, flaky, and comes out perfect every time.

1 3/4 c. flour (I prefer to measure 8.5 oz. on a digital scale)
1 tbsp. sugar
1 tsp. kosher salt (slightly heaped)
1.5 sticks of cold butter, cut into 16ths (cubes)
4 tbsp. cold water

Swirl dry ingredients in a food processor (I am personally devoted to this model). Prepare icewater by putting ice and a little water into a cocktail shaker and shake vigorously (this gets it much colder than just a glass of icewater. Then add cubed butter and pulse until a coarse meal texture is attained (pea size hunks). Then measure 4 tbsp. of ice water into the processor, pulsing a few times after each tablespoon. At this point you need to watch the texture, and continue pulsing until the dough starts to clump and look like it wants to bind together into a cohesive mass. At this point, turn out onto Saran Wrap and shape into a tight puck. Refridgerate at least a half hour. Overnight is good if possible.

Before rolling dough, remove from fridge and set on counter about 20-30 minutes. Multiply all ingredients by two for a double crust pie (shown).