Coarsely chop the pistachios.
In a bowl, mix almond flour, erythritol, and baking powder.
Add eggs, unsalted butter, and milk, and mix well.
Add the chopped pistachios to the batter and combine.
Pour the batter into a mold and bake in a preheated oven at 180°C for 20 minutes.
Cool, then cut into pieces for serving.