Preheat oven to 400°. In a large mixing bowl, whisk flours with salt and baking powder. Add butter-flavored shortening; use a pastry blender to work it in until the mixture has the consistency of fine meal. Add regular shortening, and blend until mixture looks like wet sand with pea-sized bits of shortening (Mary says this will make the crust flakier).
Add ice water 1 tablespoon at a time. Toss with a fork until dough starts to form a ball. Turn dough onto floured counter, and knead three times, until smooth. Divide dough into two balls, one slightly larger than the other.
On a floured surface, roll out larger ball to a 13-inch circle and transfer into a 9-inch glass pie plate. Dust bottom of crust with a bit of sugar and flour. Trim any excess dough that is draping over the edges of the pie plate, and set aside.
In a separate mixing bowl, prepare the filling. Whisk together sugars, flour, tapioca, and spices. Toss berries in dry mixture. Pour berries gradually into crust, holding back flour mixture with a big spoon. When the coated berries fill the bottom, pour the rest of the dry mixture on top of berries. Drizzle lemon juice over berries; dot with butter.
Roll out top crust to a 10-inch circle and set atop pie. Fold bottom crust up over top crust; crimp to seal. Cut slits in the top. Use leftover dough to make berries and leaves to decorate the top. Bake 40-45 minutes for fresh berries, 5-10 minutes longer if you're using frozen, until juices bubble up out of the vents.