Yuzu Roll Cake by ROKU
1. Lightly brush the base of a 38cm x 25cm Swiss roll tin with vegetable oil. Cut a sheet of greaseproof paper to fit the base of the tin exactly. Brush the paper with a little more oil, then dust with flour. Preheat the oven to 180°C.
2. Put the sugar and egg yolk into a large bowl and whisk with an electric hand whisk for 5 minutes. In a separate bowl, whisk the egg white only with a clean electric hand whisk until it forms soft peaks.
3. Sift half the flour into the egg yolk and sugar mixture, and fold in very carefully until no traces of flour are left. Repeat with the remaining flour; it’s important to take your time and do it gently. Then fold in half of the egg white and into the mix. Once mixed, add the remaining egg white and repeat folding into the mixture.
4. Pour the mixture into the prepared tin and use a spatula to smooth it evenly into the corners. Bake in the centre of the oven for 10-12 minutes, until golden, risen and just firm to the touch. Meanwhile, start making the Yuzu cream and Yuzu jelly.
5. When the sponge is cooked, lay out a damp clean cloth on the work surface. Lay a piece of greaseproof paper that is larger than the sponge on top and dust with flour. Run a knife around the edge of the warm sponge and turn out onto the flour-dusted paper. Peel the paper off the base of the sponge. Cut the sponge in half and trim off the edges of the sponge. Keep one half under the damp cloth.
6. Spoon one-third of the Yuzu cream onto one half of the sponge and spread it out. Then lay a few strips of Yuzu jelly and then spoon more Yuzu cream to cover the jelly, leaving a little border of clean sponge all around. *Make sure you leave some Yuzu Jelly for the decoration
7. Make an incision about 1cm in from the short edge near you, being careful not to cut through the cake: this makes it easier to roll up. Start rolling, using the incision to help you make the first turn. Use the paper to help you roll the sponge tightly. Repeat the process to make another roll.
8. Ice the top two-thirds of the surface of the cake with Yuzu cream. Create lines horizontally with a piping bag or a fork all the way from end to end.
9. Crush the remainder of Yuzu jelly into crystals and then stick them to the side of the roll, on the lowest part of the Yuzu cream icing, as if creating a dividing line between the sponge and icing.
10. Decorate the top with all the topping ingredients
To make Yuzu Cream
1. Whisk double cream with sugar until soft peaks form, then add Yuzu concentrate and whisk again until the cream texture becomes quite stiff holding shape.
To make Yuzu Jelly
1. Heat Yuzu juice in a sauce pan or microwave to about 70-80 degrees. Then add gelatine powder and mix well until all the powder dissolves. If you are using a gelatine sheet, follow the ratio according to the packet instruction.
2. Once the powder has dissolved, transfer the liquid into flat container and then keep it in the fridge for about 1 hour or until the liquid sets.
3. Slice the jelly into strips. Keep them in the fridge.