Vegan Matcha Sandwich Biscuits

MAKE THE BISCUIT DOUGH:
Sieve the plain flour, icing sugar, matcha powder, and salt together into a medium bowl. Add the cold cubed vegan butter and rub it into the flour mixture with your fingertips, working quickly to keep the butter cool, until the mixture resembles fine breadcrumbs. Press the mixture together and form into a cohesive ball of dough — do not overwork it.

ROLL AND CHILL (FIRST REST):
Roll the dough out between two sheets of non-stick baking paper to an even thickness of ½ cm (just under ¼ inch). Transfer onto a flat baking sheet, still between the papers, and refrigerate for 20 minutes until completely firm.

MAKE THE YUZU GANACHE:
Pour the plant-based double cream into a small saucepan. Add the cornflour and whisk together thoroughly until no lumps remain. Place over a medium-high heat, whisking constantly, and bring to the boil - the mixture will thicken to a heavy custard. Remove from the heat immediately and transfer into a small heatproof bowl.

MELT AND EMULSIFY:
Add the yuzu vegan chocolate and the deodorised coconut oil to the hot cream mixture and stir until fully melted and combined. Add the yuzu powder, then use an immersion blender to blend the ganache until completely smooth and glossy. Place the bowl in the freezer for 15 minutes.

SET THE GANACHE:
Remove the ganache from the freezer and blend once more with the immersion blender until properly emulsified - the mixture should look silky and cohesive. Pour into a shallow tray or dish to maximise surface area. Refrigerate for 20–30 minutes until the ganache reaches a thick, pipeable consistency that holds its shape when a spoon is lifted through it.

CUT AND EMBOSS THE FLOWERS:
Remove the dough from the fridge and carefully peel away the top sheet of baking paper. Line a clean baking sheet with fresh non-stick paper. Using a flower-shaped biscuit cutter, cut flower shapes from the dough. If your cutter has an embossing disc, leave the cutter in place after cutting and press the embosser down firmly to imprint the petal pattern. Lift each flower onto the lined baking sheet. Repeat until you have 20 flower-shaped biscuits (10 pairs). Re-roll any scraps once.

SECOND CHILL AND BAKE:
Chill the cut biscuits on the lined tray for a further 15 minutes. Preheat your oven to 160°C / 140°C fan / 325°F / Gas 3. Bake for 12–15 minutes until set and very lightly golden at the edges - they should not brown. Remove from the oven and leave on the baking sheet for 5 minutes (they are fragile when hot), then transfer carefully to a wire rack and cool completely before filling.

ASSEMBLE THE SANDWICHES:
Turn 10 of the cooled biscuits upside down on a clean work surface. Spoon the set yuzu ganache into a piping bag fitted with an 8mm plain nozzle. Pipe a neat blob of ganache onto each petal of the upturned biscuits - filling petal by petal rather than as a single central dome gives even coverage. Press the remaining 10 biscuits gently on top, right-side up, to complete the sandwiches.

PREPARE THE ROYAL ICING AND RICE PAPER FLOWERS:
Sieve the royal icing sugar into a small bowl. Add approximately 1 teaspoon of water and mix vigorously to a stiff, smooth piping consistency - it should hold a peak and not flow. Add water drop by drop if needed. Spoon into a small piping bag fitted with a writing nozzle. Using a small paper flower cutter, stamp 10 flowers from the white rice paper.

DECORATE AND SERVE:
Pipe a very small blob of royal icing into the centre of each assembled biscuit. Immediately place a rice paper flower on top, pressing it lightly into the icing to secure. Pipe a tiny dot of icing in the centre of each paper flower. Allow the icing to set briefly, then serve. Best eaten on the day of assembly.