1. Preheat oven to 350 degrees.

2. In a large bowl, whisk together gingersnap crumbs, brown sugar, flour, and salt. Add butter and stir until mixture is well combined. Press some of the mixture against the side of the bowl with your fingers. If the crumbs do not hold together, add cold water, a little at a time, up to 1 tablespoon, and stir to combine.

3. Press crumb mixture into a 9-inch pie plate, evenly covering the bottom and sides. Transfer to freezer and chill for 10 minutes. Place pie plate on a baking sheet and bake until crust is fragrant and set, about 10 minutes. Transfer pie to a wire rack; let cool completely.