Prepare the pattern 

1. Spray cake release spray on the baking pan.  Place the Halloween pattern in the centre of the pan.  Line it with the parchment paper on top.  
2. Place the butter in a medium mixing bowl and sift in icing sugar.  Beat until well combined.  The mixture should be pale and fluffy. 
3. Add in egg whites and continue to beat around 2 minutes or until well incorporated. 
4. Sift in the flour and beat the mixture until a smooth batter. 
5. Add in the activated charcoal powder and mix in very gently as the powder is very fine, using a silicone spatula. 
6. Load the batter into a piping bag. 
7. Spray a very thin layer of cake release spray onto the parchment paper to avoid the patter getting stuck once the cake is baked. Wipe off any excess with a kitchen towel. 
8. Cut a tiny hole at the top of  the piping bag and start piping following the template underneath. If you make a mess, wipe it off using kitchen paper and start again. 
9. Once happy with the pattern, place the baking pan in the freezer for about 30 mins or until the pattern is firm.

Prepare the cake batter 

1. Separate the eggs very carefully. Don’t let any yolks drop into the whites. Set the egg whites aside.
2. Add 35 grams caster sugar into the egg yolks. Beat them at medium speed until pale and almost double in volume. 
3. Add the milk, vegetable oil and vanilla extract. Continue to beat until well mixed. 
4. Sift in flour and salt, beat until the mixture becomes a smooth batter. 
5. Add a few drops of orange gel food colouring to the batter and mix well until you are happy with the colour. Use a silicone spatula to scrape around the mixing bowl to make sure everything is well mixed. 
6. At this point, let’s preheat the oven to 165 C to make sure the oven is nice and hot once the cake batter is ready to be baked.

Prepare the egg whites

1. Place the egg whites in a large mixing bowl and add in a few drops of lemon juice / vinegar / ¼ tsp of cream of tartar to stabilise them.  
2. Whisk egg whites until foamy on the surface, add in 30 g caster sugar in three stages.  Give it 30 seconds or 1 minute in between to let the sugar dissolve before adding the next.  
3. Once the sugar is added, turn the mixer at medium-high speed and continue to whisk the egg whites until stiff peaks – the egg whites will turn thick, glossy and can hold their shape.  
4. Scoop a small amount of beaten egg whites into the cake batter to loosen its texture. 
5. Scoop one-third of the meringue at a time and gently fold into the cake batter using a whisk.
6. Gently, completely fold in each portion (until you can’t see any white blobs) before adding the next portion.
7. When all the meringue is folded in, use a spatula for a final gentle mix to make sure everything is well combined.

Bake and roll the cake

1. Take the firmed pattern from the freezer and remove the original design template from under the parchment paper.
2. Pour the cake batter onto the pattern batter. Use an offset spatula to even out the surface. Drop the pan (from the height of a few inches) a few times against the work surface to get rid of any big air bubbles trapped inside the batter.
3. Bake the cake in the preheated oven at 165℃ /  325℉ for about 10 to 11 minutes or until a skewer inserted in the centre comes out clean.
4. Once the cake is done, take it out from the oven immediately. Remove the cake from the pan when you can handle it without gloves (be careful) and peel off the parchment paper on the sides.
5. Place a new sheet of parchment paper on top and flip it over. Peel off the baked parchment paper to reveal the pattern.
6. Get a clean tea towel ready on the side. Place a new sheet of parchment paper on top of the patterned side. Flip the cake over again onto the tea towel so the pattern is facing down.
7. With the help of the parchment paper and the tea towel, start rolling the cake into a log. The tea towel will keep the cake moist and soft. Cool completely on a wire rack, with the seam facing down.

Prepare the filling

1. Before whipping, chill the mixing bowl in advance.
2. Add a pinch of salt in the icing sugar.  Mix well and set aside. 
3. Add chilled double cream, icing sugar mixture and vanilla extract in the chilled mixing bowl. Whisk at medium speed.
4. Continue whisking at medium speed until it reaches a thick, firm and spreadable consistency.
5. Cover with a lid or cling film and pop it back to the fridge until needed.

Assemble and serve the cake

1. Unroll the cooled cake and peel off the parchment paper inside.
2. Scoop a generous amount of whipped cream into the curled inner edge (which will become the centre of the cake), followed by an even layer across the remainder of the flat surface of the cake, using an offset spatula.
3. Now use the parchment paper on the exterior to help roll the cake back up and with the tea towel again. Place the cake into the fridge to set, for around one to two hours.
4. Remove the cake from the fridge and unwrap the parchment paper and towel. Use a sharp knife to slice off both ends of the roll to make it look neat.
5. Serve on an elegant serving plate and enjoy. Happy Halloween!