position rack at the center of the oven and preheat to 325 degrees.
Brush a 10 inch spring foam pain with some of the butter.
Add the rest of the butter to the grahm cracker crumbs, 1/4 cup of the sugar, and a pinch of salt in a bowl. mix and press to the bottom and sides of the pan packing it tightly and evenly. Bake until golden brown 15-20 minutes
Cool the spring foam pain on a rack then cover the outside of the pan with foil.
Bring a medium pot of water to boil.
In a bowl beat the cream cheese with a mixer until smooth. Add the remaining 2 1/2 cups of sugar and beat until until just light, scraping down the sides of the bowl and beaters as neeed. Beat in the sour cream, then add the pumkin and eggs, vanilla, 1 teaspoon salt and the spices and beat until just combined. Pour into the cooled crust.
Gently place the foil covered springfoam pan (just the bottom covered) into a large roasting pan and pour the boiling water half way up the sides of the spring foam pan.
Bake in the oven until the outside of the cheesecake sets the center is still loose. About 1 hour and 45 minutes.
Turn oven off and open the door briefly to let out some heat. Leave the cheesecake in the oven for 1 more hour, then carefully remove from the roasting pan and cool on a rack. Run a knife around the edges, cover and refrigerate at least 8 hours or overnight
Bring the cheesecake to room temperature 30 minutes before serving. Unlock and remove the springform ring. To finish place a dollop of the whipped cream on each slice and sprinkle with toasted pecans.