Step by step method

1. You will need a well-greased oblong baking tin measuring 18 x 28 cm, lined with silicone paper (baking parchment), allowing the paper to come 2.5cm above the tin.
2. Preheat the oven to 180°C.
3. Begin by chopping the nuts roughly, not too small, then place them on a baking tray and toast them in a preheated oven for 8 minutes.
4. Chop up the marshmallows and white chocolate and set aside.
5. While the nuts are cooking, put the dark chocolate and Stork Bake together in a large mixing bowl fitted over a saucepan of barely simmering water, making sure the bowl doesn't touch the water. Allow the chocolate to melt, then beat it until smooth, remove it from the heat and simply stir in all the other ingredients until thoroughly blended.
6. Spread the mixture evenly into the prepared tin and bake on the centre shelf of the oven for 30 minutes or until it's slightly springy in the centre. Remove the tin from the oven and leave it to cool for 10 minutes before cutting into roughly 15 squares. Then, using a knife, transfer the squares on to a wire rack to finish cooling.