Preheat your oven to 350°F (175°C). In a mixing bowl, combine the crushed graham crackers, crushed pistachios, melted butter, and sugar. Stir until the mixture is well-combined.

Press this mixture firmly into the bottom of a greased 9x9 inch baking pan, ensuring an even layer.

Pop the crust into your preheated oven and bake for about 10 minutes, or until it’s lightly golden. When finished, remove it from the oven and allow it to cool completely.

In a mixing bowl, combine the softened cream cheese, powdered sugar, and vanilla extract. Beat together until smooth and creamy. Then, gently fold in the whipped cream until fully incorporated.

Once the crust has cooled, spread the cream cheese filling over the crust. Next, layer the blackberries evenly across the top.

Refrigerate the bars for at least 2 hours, or until firmly set.

Once set, use a sharp knife to slice the bars into squares. You can garnish them with additional crushed pistachios for an extra touch.