Preheat the oven to 350°F.
For the crust: Place the gingersnaps in a food processor. Pulse until finely ground. With the machine running, add the butter and process until evenly moist. Press the crust over the bottom and up the sides of a 10-inch deep-dish glass pie plate. Refrigerate until firm, at least 20 minutes.
For the filling: Combine the pumpkin, brown sugar, maple syrup, ginger, cinnamon, nutmeg and salt in a large bowl. Whisk until smooth. Add the eggs and whisk until smooth. Whisk in the cream and vanilla. Pour the filling into the crust.
Bake the pie until the filling is puffed on the edges and center is set, gently covering the edges with foil if the crust browns too quickly, about 1 hour. Transfer to a wire rack and let cool. Serve at room temperature or chilled.