Preheat oven to 375 degrees F. For filling, in a large bowl combine pumpkin, sugar, ginger, salt, and cinnamon. Add eggs; lightly beat with a fork to combine. Gradually add milk and maple syrup, stirring just until combined.
Pour filling into Gingersnap-Graham Crust. To prevent overbrowning, loosely cover edge of pie with foil. Bake for 50 to 55 minutes or until a knife inserted near center comes out clean. Remove foil. Reduce oven temperature to 350 degrees F.
Carefully spread Brown Sugar Meringue over hot filling; seal to edge. Bake about 15 minutes or until golden. Cool on a wire rack. Loosely cover and refrigerate within 2 hours.
Brown Sugar Meringue
In a large bowl let egg whites stand at room temperature for 30 minutes. Add vanilla, cream of tartar, and salt. Beat with an electric mixer on medium speed until soft peaks form (tips curl). Gradually add brown sugar, 1 tablespoon at a time, beating on high speed until mixture forms stiff peaks (tips stand straight).
Preheat oven to 375 degrees F. In a large bowl combine gingersnaps, graham crackers, and sugar. Stir in butter. Spread evenly on bottom and up side of a 9-inch pie plate. Bake for 4 minutes. Cool on a wire rack. Makes 1 piecrust.