In a medium bowl, combine the Greek yogurt, vanilla and honey.

Separate out 3/4 cup of the mixture and pour into a blender with the blackberries. Pulse until well combined.

Line a 1/4 sheet rimmed baking pan with parchment paper. Spread the vanilla-honey yogurt mixture evenly onto the baking sheet first. Then pour the blackberry yogurt mixture on top and swirl around, top with more blackberries and pistachios. Transfer to the freezer and freeze for 4 hours. Serve immediately and transfer any leftovers to an airtight container. Consume within a few days for best results.