YIELD: one 9-inch pie
Add the water, 1/2 cup (100g) of sugar, hibiscus powder, and ginger to a large saucepan. Boil on high until thick and glossy and reduced down to 1/4 cup (about 110g), about 30 minutes. Let cool completely. This can happen at room temperature or an ice bath to speed things up.
Meanwhile, position a rack on the lower third of the oven and set a sheet pan on it. Preheat to 400 F for at least 30 minutes.
If you want a lattice design, cut one round of pie dough into strips and set aside (a regular double crusted pie also works). Line a pie plate with the other round of pie dough.
In a large bowl, add the apples, cooled hibiscus mixture, the remaining 1/2 cup (100g) sugar. Stir in the flour.
Pour the apple mixture into the pie plate. Arrange the dough strips into a lattice. Pinch the overhanging dough and fold under itself to form a crust. Crimp or flute as desired.
Brush the pie dough with egg wash and sprinkle with the turbinado sugar. (If you’re making a regular double crusted pie, cut some slits on top to vent).
Bake the pie on the hot sheet pan until crust is golden and filling is bubbly, about 1 to 1 1/2 hours. Cover loosely with foil if the crust start looking too dark.
Transfer the pie to a wire rack and let cool for at least 4 hours.
You can slice into it while it’s still warm but I recommend chilling in the refrigerator for a couple hours to firm up. It’s way easier to slice this way.