Place your first cake on your serving plate and pipe the buttercream on top. Smooth using a palette knife, don’t worry is any of the buttercream splodges out the side. Repeat until your cake is stacked.
Using your cake smoother smooth around the sides of the cake. Don’t worry if you can see the cake through the buttercream, this is just the crumb coat. We will cover the cake soon.
If there are any gaps, pipe buttercream into the gaps and then smooth again using your cake smoother.
Once there are no gaps in your cake pop it into the fridge until the buttercream has hardened. Keep your buttercream in the piping bag and leave to one side.
Once the buttercream has hardened, pipe the remaining buttercream onto the top of the cake and around the sides.
Using your smoother, smooth around the sides, if there are any gaps fill these with the buttercream and continue to smooth around the sides until the cake is smooth. You will most likely take some of the buttercream off the cake if you do pop this back into your bowl.
Using a palette knife smooth any buttercream into the top of the cake so you have nice sharp edges.
Put the marshmallows into a heatproof bowl and put it into the microwave on 20-second bursts until they are sticky and stringy.
Nowthis is the fun/messy part. It is quite hard to explain but if you put yourfingers into the marshmallow and pick up lumps of it, the marshmallow shouldstretch, wrap it around your cake
Finish your cake off by using edible eyes or spiders.