1. Prepare the Crust

1. In a medium bowl, combine the graham cracker crumbs, sugar, melted butter, and salt.
2. Mix until the crumbs resemble wet sand.
3. Press firmly into the bottom of a 9-inch springform pan.
4. Refrigerate while preparing the filling.

2. Make the Filling

1. In a large bowl, beat the softened cream cheese until smooth.
2. Add the powdered sugar and vanilla extract, mixing until creamy.
3. In a separate bowl, whisk together the pistachio pudding mix and cold milk for about 2 minutes until slightly thickened.
4. Fold the pudding mixture into the cream cheese mixture.
5. Add the chopped pistachios and almond extract, if using.

3. Whip the Cream

1. In another bowl, whip the heavy cream until stiff peaks form.
2. Gently fold the whipped cream into the pistachio mixture until light and fluffy.

4. Assemble

1. Spread the filling evenly over the chilled crust.
2. Smooth the top with a spatula.
3. Cover and refrigerate for at least 6 hours, preferably overnight.

5. Decorate and Serve

1. Remove the cheesecake from the springform pan.
2. Top with whipped cream, chopped pistachios, and white chocolate shavings if desired.
3. Slice and serve chilled.