Place the graham crackers and coconut into a food processor and pulse until they form a very fine crumb. Pour into a bowl and add the baking powder and mix together.

Place the butter in a large bowl and beat with an electric mixer until light and smooth. With the mixer still on, slowly add the sugar. Keep whipping for 5 minutes until it is light and fluffy.

Add the egg yolks one at a time, mixing well after each addition. Then add the vanilla extract and mix well.

Add the graham cracker mixture in 3 additions, alternating with milk (graham crackers > milk > graham crackers > milk > graham crackers). Mix until fully combined, then add the chocolate chips and mix again.

Place the egg whites in a separate bowl, and beat with an electric mixer until they become frothy. Add the cream of tartar and continue whipping until you reach stiff peaks. Place ¼ of the egg whites into the graham cracker batter and gently mix together. Then add the remaining egg whites and gently fold into the batter, keeping it as airy as possible.

Pour the batter into 2 buttered 9-inch round cake pans. Bake at 350F for 25-30 minutes until fully cooked.

Allow the cakes to cool in the pan for 10 minutes, then turn out onto a cooling rack and completely cool.

Fully dissolve the cocoa powder in the boiling water and allow to cool.

Place the butter, confectioner’s sugar and salt into a large bowl and beat with an electric mixer until pale and fluffy. Then add the melted (and cooled – this is important, because warm chocolate will melt the butter) semisweet chocolate, and mix until fully combined. Then add the cocoa liquid, mix together.

Place about ¼ of the frosting and place it in a smaller bowl. Add the chocolate chips and marshmallows and mix well.

Once the two cakes have fully cooled, stack the cakes on top of each other. Gently round the edges of the top layer of the cake, so that it looks rounded and slightly like a dome.

Spread the frosting filled with chocolate chips and marshmallows between the two cakes, leaving about ½ inch of room from the edges of the cake. Place the second layer on top and gently press down, to even out the filling. Then transfer the cake to a serving tray of your choice.

Coat the cake in a thin layer of frosting as a crumb coat, and place the cake in the fridge for 15 minutes for the frosting to stiffen. Then coat the cake in a thicker layer of frosting with the remaining frosting.

Stick the mini white marshmallows onto the entire surface of the cake, making sure to stick the flat sides (rather than the round, curved sides) onto the cake. The cake will look like one big marshmallow! Place the cake in the fridge for about 15 minutes for the buttercream to stiffen.

Then roast the marshmallows! “Roast” the marshmallows by holding a kitchen blow torch about 15 cm away from the surface of the cake and rotating the torch in a circular motion. Just lightly brown the marshmallows, to prevent the buttercream and marshmallows from melting.