Heat the oven to 200C/180C fan/gas 6. Put the caster sugar in a small roasting tray lined with baking parchment. Shake to level out the sugar and heat in the oven for about 5 mins until hot but not melting (this helps stabilise the egg whites and give a smooth and glossy meringue).

Beat the egg whites in a stand mixer with the cream of tartar. Whisk slowly at first, gradually increasing the speed until the egg whites are at the stiff peak stage, about 5 mins. It’s important not to over-whisk the egg whites. Remove the sugar from the oven as soon as the whites are stiff.

Turn the oven down to 110C/90C fan/gas 1/4, leaving the door ajar to help it cool down quickly – your meringues need to be baked at a low temperature.

Turn the mixer up to full speed and start adding the sugar one tablespoon at a time. You egg whites should maintain their volume as you keep adding sugar – if you see it starting to collapse, stop adding sugar and allow the mixture to stiffen and rise before adding the rest, a spoonful at a time.

Line three baking trays with baking parchment, and put the ‘B’B’, ‘O’O’ ‘O’’O’ templates underneath so that you can trace them. Fill your piping bag with the meringue, about two-thirds of the way up. Avoid over-filling the bag or you'll find it difficult to pipe – you can add more into the bag later.

Cut a hole at the tip of the bag, around 1cm wide, and hold the bag near to the bottom while your other hand holds the top, keeping the top of the bag closed so there are no meringue spillages.

Start with the piping bag directly upright and squeeze gently with the bottom hand to trace around the edge of the letters to make a meringue border; once you have the shape, you can fill it in. Smooth any rough lines and edges with the back of a spoon or mini palette knife.

To form the ghosts, hold the bag steady about 1cm above the tray and squeeze the bag from the top to start forming the body of your ghost. Keep the bag completely still while squeezing, using your lower hand to keep the bag steady. Stop squeezing once the meringue hits the tray. Lift the piping bag a tiny amount, without creating a break between the meringue on the tray and the meringue left in the piping bag. Drop the bag back down again and squeeze gently to form the top part of the ghost's body - lift the piping bag straight up to leave a cute peak on the top of your ghosts' heads. This will take a bit of practice so don’t worry if you don’t get it right the first time, just keep going and get a feel for it.

Place your six letters and the mini ghosts in the oven for 2 hrs until the meringue is crisp on the outside and mallowy in the middle. Turn off the oven and leave the pavlova to cool in the oven. If after 2 hrs your meringue is too gooey in the middle, bake for another 30 mins, then leave it to cool in the oven again. Will keep for one week stored loosely in a tin somewhere cool and dry.

To make the the raspberry ‘blood’ coulis, put the frozen berries in a pan over a medium heat, then add a tbsp of honey and a squeeze of lemon juice. Cook for 5 mins. For a smooth sauce, strain through a fine sieve, then leave to cool. Will keep for up to three days in the fridge.

When you're ready to serve, place the bottom letters on the board to spell out ‘BOO’ on a lovely serving platter or board. If you had enough mixture to make mini meringue ghosts, add their faces. We like to draw on two big, droopy eyes and an open mouth so you can really imagine them making spooky, ghostly sounds. If you don’t have an edible pen, you can gently melt 50g dark chocolate in a microwave and use a small paint brush to paint on the faces.

Whip the double cream until soft peaks form. Fill your second piping bag with your whipped cream and cut a small hole, around 2cm, at the end. Pipe blobs all over the letters – you can add some sliced berries on top of the cream at this stage. Carefully place the second letters on top. Repeat the cream blobs on the top layer. Decorate with the blackberries, raspberries, edible flowers and ghost meringues. Drizzle with some of the raspberry ‘blood’ coulis. Feel free to add sprinkles, macarons, Halloween sweets, a drizzle of dark chocolate, edible gold leaf or freeze-dried raspberry pieces – go to town with what you have! We recommend eating it the same day, but it will keep for a day in the fridge.