Instructions

1. Prepare a round 9 inch cake tin by lining the bottom with greaseproof or parchment paper and greasing the sides well with butter. If you haven’t already, crush your biscuits until they resemble fine crumbs using a food processor or doing it by hand with a plastic ziplock bag and a rolling pin.
2. Pour your biscuit crumbs into a bowl. Place your butter in a separate bowl, roughly chopped, and melt in the microwave – stirring in-between 15 second bursts. Then pour your melted butter over the biscuit crumbs and stir until combined. Pour the wet biscuit crumbs into your prepared tin and use the back of a spoon to press down gently until it forms a nice even layer. Pop your base into the fridge.
3. Next, preheat your oven to 160 C (320 F). Then add your chocolate pieces and chopped butter into a heatproof bowl. Place over a medium saucepan that is filled with a bit of water, say 5cm (2 inches) high or so. You need to ensure the bowl will not touch the water below. Place on the stove on medium-low heat and stir gently while the chocolate and butter gradually melt. Once completely melted, remove the bowl from the heat and leave to cool slightly.
4. Next add your sugar and vanilla to your chocolate mixture and beat on low with an electric mixer until combined. Then add your eggs, one at a time and beat again. Lastly, sift in your flour and cocoa powder and beat briefly until mixture is smooth. Pour your brownie batter over your biscuit base and pop into the oven for around 38-40 minutes or until the brownie no longer wobbles in the middle. Leave to cool completely on a wire rack.
5. Once your pie has cooled completely, line the top with one layer of white marshmallows. Pop until the grill or broiler on low and let the marshmallow slowly toast and melt in the middle. Watch them closely though as it happens fast! Alternatively, you could also use a kitchen torch. Once the marshmallows are done, you can cut your pie into slices and devour.