Preheat your oven to 175C / 350F (fan off), 155C / 310F (fan on). For this recipe I used a jelly roll pan measuring 37 x 24cm / 14.5 x 9.5-inches. Spray the bottom only with oil spray and line with baking paper. Set aside.

Combine dry ingredients - To a small mixing bowl, add the flour, baking powder and salt. Whisk to combine. Set aside.

Whip meringue - To a separate medium sized mixing bowl, add the egg whites and cream of tartar and beat on medium speed using an electric hand mixer until you reach soft peaks, about 1 minute. Begin slowly adding (100g) of the caster sugar, about 1 tsp at a time, while the mixer is on high speed. The meringue will thicken and become glossy. Continue beating for 2-3 minutes until the sugar is mostly dissolved. Set aside.

Whip egg yolks and sugar - Add the egg yolks, warm water, remaining sugar (60g) and vanilla extract to a separate large bowl and whip on high speed for 5 minutes until it becomes thick and pale. Then, while the mixer is on high speed slowly drizzle the oil in until well combined.

Fold meringue through the egg yolks - Add half of the egg white mixture to the egg yolk mixture and use a spatula to gently fold through until almost completely combined. Add the remaining egg white mixture and repeat until mixture is uniform.

Add dry ingredients - Sift half the dry ingredients over the egg mixture. Gently fold through until well combined. Sift the remaining dry ingredients in and repeat. The batter will be thick, airy and light.

Bake - Add the batter to the prepared baking tray and use a spatula to gently spread the mixture as evenly as you can. Bake for 14 minutes.

Cooling down - As soon as the sponge comes out of the oven, cover the pan with foil and seal the edges to trap the steam. This keeps the sponge soft and flexible, making it easier to roll without cracking. Let it cool at room temperature for one hour. Just above room temperature is fine, but don’t cool it in the fridge or a cold room or it will stiffen and crack when rolled.

Add all the ingredients in a large mixing bowl (glass or metal, not plastic) and use an electric hand mixer fitted with beaters or a stand mixer fitted with a whisk attachment to whip until you reach stiff peaks. This usually takes about 3 - 4 minutes to achieve. What you’re looking for is a smooth but stiff whipped cream, not one that looks split. If it looks split or separated, congratulations, you’re on your way to making butter, start again!

To fill the cake - Spread a thin even layer of jam over the cooled sponge. It must be a thin layer. Too much will pool as you roll, ruining the shape and swirl.

Pipe the cream on top (super important!) - The best way to get an even layer of cream is to pipe it on. Add the Chantilly cream to a piping bag and pipe a perimeter of cream around the sponge, leaving a 2cm border along both short sides. Then fill in the center with more piped cream. Use a spatula to spread evenly. This gives you an even layer of cream and helps contain the filling as you roll, keeping the swirl neat and the cream from spilling out.

To roll - Use one hand to lift the baking paper up and away from the sponge while using your other hand to gently guide and hold the roll in place as it curls over itself. Roll slowly and tightly, keeping even pressure without squashing the filling. Once rolled, carefully lift it off the baking paper and place it seam side down on your serving plate to help seal the roll.

Chill and finish - Chill the rolled-up cake for an hour. Then trim 1cm off each end with a sharp knife to neaten. You can serve it straight away, but chilling for 1 hour makes slicing easier and cleaner