Gingersnap crust

1. Preheat the oven to 350°F.
2. Crush the gingersnaps into crumbs with a food processor or in a bag using a rolling pin or heavy can.
3. Add all the ingredients to a bowl. Stir and toss until coated in butter.
4. Pour the crumbs into a 9" pie plate, pressing it evenly across the bottom and sides of the pan.
5. Bake the crust for 7 minutes, then cool it and refrigerate until the apple filling is ready.
6. Turn the oven up to 400°F.

Apple filling

1. Melt the butter over medium heat in a large nonstick skillet.
2. Saute the fresh ginger in the butter for a few minutes, then add the diced apples.
3. Toss the apples in the butter and then add the flour, sugar, cardamom, turmeric, and salt.
4. Cook the apples for 7 minutes or until they start to soften, stirring more often as it thickens. (The apples do not need to be completely soft, as they will continue to cook in the pie when it's baked.)
5. If the sauce thickens too much, add water, a few tablespoons at a time, to keep it from burning.
6. Cool the apples to room temperature before adding them to the refrigerated crust.

Topping

1. While the apple filling cools, combine the flour, sugar, cardamom, and salt in a small bowl.
2. Grate the cold butter using the large holes of a cheese grater. Add the grated butter to the bowl and toss in the flour mixture. Set the bowl in the freezer until you're ready to use it.
3. Before adding the topping to the pie, break the grated butter into smaller pieces by squeezing with your hands.
4. Pour the topping onto the pie, spreading it evenly to the edges.
5. Bake the pie in a 400°F oven for 15 minutes, then turn the heat down to 350°F and continue to cook it for about 40 minutes, or until the top has risen and browned.