Prepare the Crust: Mix ground biscuits with melted butter until well combined. Press this mixture into the bottom of an 8-inch cake pan and refrigerate to set.

Make the Filling: In a large bowl, beat cream cheese, pistachio spread, heavy cream, and powdered sugar with an electric mixer until smooth and creamy, about 2 minutes.

Assemble: Remove the crust from the refrigerator and evenly spread the pistachio filling over it. Refrigerate for about 30 minutes to firm up slightly.

Prepare the Topping: Heat heavy cream, pistachio spread, and a pinch of salt in a saucepan until hot. Remove from heat and add white chocolate, stirring until smooth.

Finish the Cheesecake: Pour the white chocolate mixture over the chilled cheesecake. Return to the refrigerator to set completely.

Garnish: Sprinkle chopped pistachios and rose petals over the top before serving if desired.