Making the mold: Take a rectangular baking pan and cut two wooden sushi sticks to the width of your pan. Place them at the bottom and cover with a piece of baking paper. This helps to create a mold for your chocolate shape with the filling.
Baking the frangipane: Evenly distribute the pistachio frangipane over the mold and bake for 12-15 minutes in a preheated oven at 185°C. Let it cool completely before proceeding.
Removing the mold: Carefully remove the frangipane from the mold and cut the sides loose if necessary. Place the frangipane on a rack with a baking sheet underneath to catch the chocolate.
Melting the chocolate: Melt the dark chocolate in a bain-marie or in the microwave (stir every 15 seconds to prevent the chocolate from burning).
Assembling: Pour the melted chocolate over the frangipane. Drizzle the pistachio butter on top and sprinkle with the coarsely chopped pistachios and sea salt flakes.
Setting: Let the bar set in the refrigerator. Once the chocolate is hard, you can break it into pieces for that delicious 'crack'.
Tips
You can easily replace the pistachiorangipane with marzipan or a nut mixture, depending on your preference. Always keep the bar in the fridge to keep the chocolate nice and crispy.