Place the well-drained cherries in a large bowl. Have the other filling ingredients nearby, but don’t add them yet.
Roll out one disk of dough for your bottom crust. Ease it into a 9-inch pie pan and trim the edges. Put it in the refrigerator to chill.
Roll out the second disk of dough for the top crust. If it's still nice and cold, use a fluted pastry wheel to cut into about 12 strips, each about ¾ inch wide. (If the dough has warmed up & softened a bit, chill it until it's firmer, and then cut.) Put the strips on a baking sheet in the refrigerator.
Add the almond extract, sugar, salt and tapioca flour into the cherries, stirring briefly to combine.
Take the bottom crust out of the refrigerator. Pour the cherry filling into the bottom crust.
To weave the lattice top:
Divide your dough strips in half, making sure that each set has long strips and shorter ones.
Arrange set #1 in evenly spaced parallel lines across the fruit filling. Fold back every other strip. Take the longest of the remaining strips (set #2) and lay it across the pie at a diagonal.
Replace the folded-back strips over this long strip.
Now fold back the strips of set #1 that haven't been folded back yet. Lay down the next-longest of your set #2 strips, and unfold the folded ones on top of it.
Continue in this way until all your strips have been used and your lattice is woven.
Trim the edges of the pie all around. Finish the edges by folding the fluted strips under the rim of the bottom crust. Crimp lightly.
Chill the pie in the freezer for 20 minutes while the oven is preheating to 425.
Take the pie out of the freezer and brush a thin coating of beaten egg white across the top and edges. Sprinkle liberally with sugar.
Bake at 425 for 20 minutes. Turn the oven down to 375 and bake for another 45 minutes or so, turning the pie after about 20 minutes to ensure even baking.
Bake until the pie is deep golden brown and you can see juices are bubbling thickly in the lattice openings.
Let cool completely to room temperature.
This pie, like any fruit pie, is best left to set for at least 8 hours before serving.