Preheat oven to 400°F.
Slice phyllo dough into thin strips then bake for 5–7 minutes, stirring halfway through, until evenly toasted and golden brown.
Let cool for 10 minutes.
Place pistachio cream in a large bowl, then mix in toasted phyllo strips and protein powder until well-combined.
Place mixture on a silicone baking mat or parchment paper and form into a 4x8-inch rectangle.
Refrigerate for 30 minutes.
Place chocolate chips in a heatproof bowl.
Microwave for 45–60 seconds, then stir and repeat until the chocolate is just melted.
Set aside.
Cut chilled pistachio mixture into 1-inch squares, then use a fork to dip squares into melted chocolate.
Place chocolate-covered truffles on a parchment-lined baking sheet and sprinkle with a pinch of chopped pistachios.
Refrigerate for 30 minutes before serving.