In a mixing bowl, combine the crushed vanilla wafer crumbs, granulated sugar, and salt. Melt the unsalted butter and pour it into the crumb mixture, stirring until fully combined. Firmly press this mixture into the bottom and up the sides of an 8 or 9-inch springform pan. Chill the crust in the refrigerator for 30 minutes to set.

Beat the cream cheese in a large bowl until smooth and creamy, about 2-3 minutes. Gradually add the instant pistachio pudding mix, vanilla extract, pistachio extract, and powdered sugar, mixing until well combined without lumps.

Slowly pour in the heavy cream while mixing on low speed. Increase speed and whip until light, fluffy, and holds soft peaks, about 3-5 minutes.

Transfer fluffy pistachio filling into the prepared crust. Smooth the top with a spatula. Cover with plastic wrap and chill in the refrigerator for at least 6 hours, or overnight.

Make whipped cream by beating heavy cream with powdered sugar and vanilla extract until stiff peaks form, about 3-4 minutes.

Spread or pipe the whipped cream on top of the chilled cheesecake and garnish with chopped pistachios. Slice and serve chilled.