Grease and line a large slice tray 25cm x 35cm with baking paper
Preheat oven to 160 degrees fan forced and place rack into middle of oven
Place a container on top of TM bowl and weigh in flour, put aside with a sieve as you will be sieving the flour into the TM bowl … it is important not to “whip” the flour into the egg mix or you will deflate the mixture
Also place 2 tsp water into a small container and put aside with the flour (you will add the flour and water at the same time)
Place an extra piece of baking paper on a silicon mat or tea towel ready for when the cake comes out of the oven - sprinkle over this baking paper the extra caster sugar and leave aside
Insert butterfly into TM bowl
Place eggs, sugar, vanilla and salt into TM bowl and mix 20 seconds / speed 2 just to combine the ingredients to start with
Then mix 6 minutes / 37 degrees / speed 4 / MC off, scrape around the sides of the TM bowl
Continue beating 6 minutes / NO TEMP / speed 4 / MC off
PS: this recipe was tested in a TM5 and TM6, so if using a TM31 if there is any "spitting" of the mix out of the MC opening, then place the ™ basket on top of the lid if it bothers you
Scrape lightly around sides of bowl
Sift over the mixture in the TM bowl the plain flour and add in the water and mix 4 seconds / speed 3
Gently lift off the butterfly and tap it against the top insides of the TM bowl to dislodge the mix that is on it, and put aside
Scrape around the top sides of the bowl where you tapped the butterfly, and if there is any flour remaining on top of the mix, very gently fold it into the mixture with just one or two strokes of your spatula
Pour the mixture over the baking tray and use an offset spatula, or back of a spoon, to gently spread it evenly over the tray … try not to press down on the mix more than is necessary otherwise you will release air from the mix, and try to make it even so that you don't have thin areas which will cook quicker than the rest making it more brittle for rolling
Place tray into oven and bake for 15 minutes until golden, lightly press the top of the sponge to check if it is ready as it should spring back, but if it doesn’t then bake for a further 2 minutes (it takes 15 to 17 minutes in my oven depending on the flour used)
Remove the tray from the oven, position it on its longer side in an upward angle against the baking paper lined silicon mat or tea towel, and then turn the tray over allowing the sponge to fall on the caster sugar (be careful as the baking tray is hot ... with the baking paper still on the base of the sponge you should be able to move it around a little to ensure it is sitting evenly on the sugar)
Carefully remove the paper on the base of the cake … don’t worry if some little bit of cake sticks ... this happened to me the first time so I think my sponge needed to cook an extra minute or so, but it didn't happen to me with my later bakes
Lightly score a line 2.5cm in from the narrow end of the sponge closest to you … do not cut all the way through … this scoring will help give you a nice roll when you fill the sponge
With the baking paper/sugar still in place, roll the sponge up from the scored edge until it is completely enclosed (do not compress the sponge, you are just rolling it up) and place into a tea towel
Put rolled up sponge on a cooling rack to cool completely before filling