Instructions

1. To make the meringues, line three baking trays with baking or parchment paper. Preheat oven to 170 C (340 F) standard / 150 C (300 F) fan-forced.
2. Add egg whites to a large mixing bowl or the bowl of your standing mixer. Beat on low for a minute or two until the egg whites start to turn white and foamy, then turn up to medium and until soft peaks form.
3. At this stage, continue to beat and slowly add in your sugar, just one tablespoon at a time. Once all the sugar has been added, continue to beat your mixture until it is stiff and glossy and almost tripled in volume.
4. Once the egg whites have formed stiff peaks, gently fold through the cocoa powder. Then spoon out your meringue mixture onto your baking trays, dividing it into three. Spread each meringue into a large circle and try and make all the meringue mounds a similar size. Then pop in the oven for 35 minutes.
5. Turn the oven off and leave the meringues inside for 2-3 hours. This will help them to slowly cool and will reduce any cracks. Then remove from the oven and store in an airtight container until you are ready to decorate.
6. Next chop your dark chocolate into small chunks and place into a bowl. Then heat 1 cup of your cream in a small saucepan on a medium-low heat until it is warm (do not boil), then pour over your dark chocolate and leave it for about 2-3 minutes. Then whisk your dark chocolate mixture until it is smooth. Leave it to cool for a few minutes.
7. Meanwhile start whipping the remaining 1 and 1/2 cups of cream until it resembles stiff peaks. Then fold your whipped cream into your chocolate mixture very gently until fully incorporated. Refrigerate the chocolate cream for an hour or two until it thickens slightly.
8. When you are ready to assemble your cake, place all your marshmallows out onto a tray or plate. To toast them, either use a blow torch to lightly brown them until they go lovely and melty or pop them in the oven under the grill or broiler until golden brown.
9. To assemble, place one meringue layer onto your serving plate. Then add one third of the chocolate cream and smear it over the top. Add a handful of crushed graham cracker crumbs. Then scatter over a few toasted marshmallows. Then add the next meringue and repeat with the chocolate cream, graham crackers and more marshmallows. Finally, add the last meringue layer and add a final topping of chocolate cream, graham crackers and a few more marshmallows.