Prepare the springform pan so that no water leaks into it while cooking. Place a large 18-inch by 18-inch square of heavy duty aluminum foil on a flat surface. Place the springform pan in the middle of the foil. Gently fold up the sides of the foil around the pan. Make sure to do this gently so that you don't create any holes in the foil. If there are any holes, water will get into the pan and ruin the crust. Repeat two more times.
Preheat oven to 350°F, with rack in lower third of oven. Pulse the graham crackers in a food processor or blender until finely ground. Put in a large bowl, and stir in the sugar and salt. Use your (clean) hands to stir in the melted butter. Use your hands to press down graham cracker crumbs form even layer of graham cracker crumbs.
Put the graham cracker crumbs in the bottom of the springform pan. Gently press down on the crumbs using your fingers, until the crumbs are a nice even layer at the bottom of the pan, with maybe just a slight rise along the inside edges of the pan. Be careful as you do this, as not to tear the aluminum foil. Place in the oven for 10 minutes. Remove from the oven and let cool. Reduce the oven temperature to 325°F.
Make the filling.
Cut the cream cheese into chunks and place in the bowl of an electric mixer, with the paddle attachment. Mix on medium speed for 4 minutes until smooth, soft and creamy. Add the sugar, beat for 4 minutes more. place cream cheese in mixer beat until smooth.
Add the salt and vanilla, beating after each addition. Add the eggs, one at a time, beating for one minute after each addition. Add the sour cream, beat until incorporated.
Add the heavy cream, beat until incorporated. Remember to scrape down the sides of the mixer bowl, and scrape up any thicker bits of cream cheese that have stuck to the bottom of the mixer that paddle attachment has failed to incorporate.
Cook the cheesecake.
Place the foil-wrapped springform pan in a large, high-sided roasting pan. Prepare 2 quarts of boiling water. Pour the cream cheese filling into the springform pan, over the graham cracker bottom layer. Smooth the top with a rubber spatula.
Place the roasting pan with the springform pan in it, in the oven, on the lower rack. Carefully pour the hot water into the roasting pan (without touching the hot oven), to create a water bath for the cheesecake, pouring until the water reaches halfway up the side of the springform pan, about 1 1/4 inches. (Alternatively you can add the water before putting the pan in the oven, whichever is easier for you.) Cook at 325°F for 1 1/2 hours.
Turn off the heat of the oven. Crack open the oven door 1-inch, and let the cake cool in the oven, as the oven cools, for another hour. This gentle cooling will help prevent the cheesecake surface from cracking.
Cover the top of the cheesecake with foil, so that it doesn't actually touch the cheesecake. Chill in the refrigerator for a minimum of 4 hours, or overnight.
Prepare sour cream topping.
Place sour cream in a medium sized bowl, stir in the powdered sugar and vanilla, until smooth. Chill until you are ready to serve the cake.
Note that this recipe produces enough sour cream topping for a thick topping and some extra to spoon over individual pieces of cheesecake, if desired. If you would like a thinner layer of topping and no extra, reduce the sour cream topping ingredients in half.
Prepare the raspberry sauce.
Place raspberries, sugar, and water in a small saucepan. Use a potato masher to mash the raspberries. Heat on medium, whisking, about 5 minutes, until the sauce begins to thicken. Remove from heat. Let cool.
Prepare the cake to serve.
Remove the cake from the refrigerator. Remove the foil from the sides of the pan, and place the cake on your cake serving dish. Run the side of a blunt knife between the edge of the cake and the pan. Dorie recommends, and we've done with success, that you use a hair dryer to heat the sides of the pan to make it easier to remove. Open the springform latch and gently open the pan and lift up the sides.
Spread the top with the sour cream mixture. Serve plain or drizzle individual slices with raspberry sauce.