Tip the biscuits into a food processor and blitz to fine crumbs. Pour in the melted butter and blitz again to combine. Line the side of a deep 20cm springform or loose-bottomed cake tin with baking parchment. Tip in the crumb mixture and press it into the base and up the side of the tin using the back of a spoon. You should be able to press the mixture about halfway up the side, but don’t worry if the edge is slightly uneven – this will add a spookily craggy effect to the cheesecake. Chill in the fridge while you make the filling.

Tip the marshmallows and milk into a saucepan set over a low-medium heat and stir until the marshmallows have melted. Leave to cool for a few minutes.

Tip the soft cheese, cream and vanilla extract into a large bowl and beat together using an electric whisk. Pour in the still-warm marshmallow mixture and mix again until smooth. Remove the chilled biscuit base from the fridge and scrape in the marshmallow cheesecake filling. Smooth the top and chill for at least 2 hrs. Will keep chilled for up to a day.

Heat the oven to 120C/100C fan/gas 1 and line a baking tray with baking parchment. Put the egg whites in a large, clean bowl with a pinch of salt and beat with an electric whisk until foamy – they should hold soft peaks when you lift out the beaters. Beat in the sugar 1 tbsp at a time until fully incorporated and the meringue is thick, shiny and holding stiff peaks.

Spoon the meringue into a piping bag fitted with a large round nozzle. Holding the nozzle directly above the lined tray, pipe little blobs to make the meringue ghosts. Bake for 1 hr 30 mins, then leave to cool.

When the meringues are cool, use an icing pen to draw faces on them. Carefully remove the cheesecake from the tin and put on a plate or cake stand. Arrange the ghosts on top just before serving. Will keep in the fridge for up to two days.