I use home-made pistachio butter because the store-bought one is difficult to find and expensive. I use this simple recipe from The Healthy Maven: http://www.thehealthymaven.com/2013/10/homemade-pistachio-butter.html
For the berries, I recommend raspberries, blackberries or/and red currants. —MarieGlobetrotter
What You'll Need
homemade pistachio butter
In a bowl, whisk together mascarpone, pistachio butter, almond powder, egg and sugar until smooth. If too thick, add a little bit of milk
Pre-heat your oven to 375F
Butter a baking dish and pour in the batter. Using the berries of your choice, add them to the batter.
Bake for 30-35 minutes until a firm and slightly golden on top