Make the crust: Preheat the oven to 325˚. Combine the crushed cookies, melted butter and salt in a large bowl. Press into the bottom of a 9-inch round springform pan. Bake until golden, 15 to 18 minutes. Transfer to a rack; let cool 20 to 30 minutes.
Make the filling: Beat the cream cheese in a large bowl with a mixer on medium speed until smooth, about 1 minute. Add the maple sugar and beat, scraping down the bowl as needed, until light and fluffy, about 2 minutes. Reduce the mixer speed to low and beat in the sour cream. Add the eggs, one at a time, and beat until combined. Beat in the maple syrup and vanilla until smooth.
Brush the side of the pan above the crust with melted butter. Wrap the outside of the pan (bottom and halfway up the side) with foil to prevent leaks; set in a large roasting pan. Pour the filling into the prepared crust.
Transfer the cheesecake in the roasting pan to the oven and carefully pour boiling water into the roasting pan so it comes about halfway up the side of the springform pan. Bake until the edges of the cheesecake are set but the center still jiggles slightly, 1 hour 15 minutes to 1 1/2 hours. Turn off the oven and open the door for 5 seconds to let out some heat. Close the oven door and leave the cheesecake in the oven until fully set on top but the center still jiggles slightly, about 1 hour.
Remove the cheesecake from the water bath and remove the foil. Transfer to a rack and let cool 2 hours in the pan. Run a thin knife around the edge of the cheesecake to loosen (do not remove the springform ring), then cover and refrigerate until chilled and set, at least 8 hours or overnight. Serve with maple syrup for drizzling.