1. Preheat oven to 325°F (163°C). Grease a 9-inch springform pan and line the bottom with parchment paper.

2. In a bowl, mix pistachio crumbs, sugar, and melted butter until combined. Press mixture firmly into the bottom of the prepared pan to form the crust. Bake for 8–10 minutes, then let cool.

3. In a food processor or blender, puree blackberries with honey. Strain to remove seeds, then stir in cornstarch and cook over medium heat for 2–3 minutes until slightly thickened. Cool completely.

4. In a large bowl, beat cream cheese and sugar until smooth. Add eggs one at a time, beating after each addition. Mix in sour cream, vanilla, and lemon juice until just combined.

5. Pour half the cheesecake batter over the crust. Add spoonfuls of blackberry puree and swirl gently with a knife. Repeat with remaining batter and puree for a marbled effect.

6. Bake for 55–65 minutes, or until the center is just set. Turn off the oven, crack the door, and let cheesecake cool inside for 1 hour.

7. Chill in the refrigerator for at least 4 hours or overnight before slicing.

8. Top with extra blackberry puree and chopped pistachios to serve.