Preheat oven to 350 degrees F.
In your food processor, crush the graham crackers until they are fine crumbs. Add 6 tbls melted butter to the crumbs, and 4 tbls sugar. Mix well.
Press into a spring form pan, use a flat bottomed glass to help press crumb mixture into the bottom and about ½ inch up the sides of the pan.
Bake for 8 minutes, then remove from oven.
Fill a roasting pan, or any larger pan with an inch of water, and set it on the middle rack of the oven.
Reduce the oven temperature to 300.
Wrap the spring form pan with aluminum foil, making sure the edges of the foil fold up most of the way up the spring form pan. If there is a place for water to seep in, it will. Then your cheesecake crust will be soggy. I like to use extra wide foil and do 2 layers in case 1 pierces.
In your mixer, beat the cream cheese until its smooth. Scrape down the sides of the bowl once or twice with a rubber spatula.
Add the sugar, sour cream, extracts, and salt.
Next add in the pistachio pudding mix.
Then add your eggs and beat on low speed only until you see they are thoroughly mixed in.
Pour the cheesecake batter into the prepared spring form pan.
Bake cheesecake for 1 hour and 15 minutes at 300.
The center should still be a bit jiggly at this point, but turn the oven off, and leave the cheesecake in there to rest.
After half an hour you can crack the oven door.
Leave it for another hour then lift it gently out of the water onto the counter, where it will rest for another hour.
Move it into the fridge then for over night.
How to make the sour cream frosting:
Whisk ½ cup cream until it has stiff peaks. Mix in ½ cup sour cream and ¼ cup powdered sugar. Whisk until combined.
How to Assemble:
After the cheesecake has had a good nights sleep in the fridge, take it out.
Run a thin knife under hot water, and then around the edge of the cheesecake.
Release the spring form.
Scoop the icing onto the center and spread it out evenly on top of the cheesecake. Stay just a hair away from the edge.
Return to fridge where the icing will set just a bit.
Adding pistachios to top: optional.