Preheat oven to 325°F and line a 12-cup muffin tin with paper liners.
Mix graham crumbs, 2 tbsp chopped pistachios, and melted butter; press 1 tbsp into each cup for crust.
Beat cream cheese and sugar until smooth, add egg, sour cream, vanilla, rosewater, and salt; mix until combined.
Fold remaining chopped pistachios into filling and divide among cups.
Bake 15–18 minutes until edges set and centers slightly wobbly; cool in pan 30 minutes then chill 2 hours.
Garnish with reserved pistachios before serving.