1. Preheat oven to 325°F (163°C). Line an 8×8-inch baking pan with parchment paper, leaving an overhang for easy removal.

2. In a food processor, pulse pistachios until finely ground. Add graham cracker crumbs, sugar, and melted butter; pulse until combined.

3. Press mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then let cool slightly.

4. In a large bowl, beat cream cheese and sugar until smooth and creamy.

5. Add eggs one at a time, mixing after each addition. Blend in vanilla and sour cream until just combined.

6. Toss raspberries with flour to prevent sinking and gently fold them into the cheesecake batter.

7. Pour batter over the cooled crust and smooth the top.

8. Bake for 35–40 minutes, or until the center is set and only slightly jiggly.

9. Cool completely, then refrigerate for at least 3 hours or until firm.

10. Before serving, sprinkle with chopped pistachios and garnish with extra raspberries if desired.