Start by making the filling. Put all the ingredients in the bowl of an electric mixer and beat until light and fluffy.

Set it aside.

Pre-heat the oven to 180C (356F) fan-forced and line two baking trays with baking paper (or grease them).

In the bowl of an electric mixer, beat the butter, brown sugar and vanilla together until light and creamy.

Add the eggs one at a time and beat each one in well.

Pour in the melted chocolate and mix it through.

Add the sifted flour, baking powder and cocoa and beat until they are just mixed in.

Take the bowl off the stand and scrape down the sides.

Stir through the chopped chocolate.

Using a tablespoon of dough, roll it into a ball and flatten it between your hands (if the dough is too sticky, put it in the fridge for 10 - 20 minutes to firm).

Spoon a teaspoon of peanut butter filling into the middle and fold the edges up and over to enclose it.

Lay the dough on the baking tray. Repeat with the rest of the dough, leaving at least 3 cm between each ball.

Sprinkle each one with a little bit of sea salt.

Bake for 10-12 minutes.

Let them rest on the trays for 5 minutes (or until they firm up) and then transfer them to a wire rack to cool completely.