- Lemon: 1, finely grated zest
- Butter: 125g (4½oz)
- Caster sugar: 125g (4½oz)
- Egg: 1, medium
- Self-raising flour: 175g (6oz)
- Plain flour: 150g (5¼oz)
- SK Professional Instant Mix Royal Icing: 400g (14oz) White
- SK Professional Liquid Food Colours: Cyclamen (Ruby) and Rose
- SK Designer Metallic Lustre Dust Food Colour: Rose Gold
- Clear alcohol, e.g. vodka or gin
- Eddingtons Heart-Shaped Cookie Cutter: 8.5cm (33/8")
- SK High-Quality Paintbrush: no. 1
Makes 12 Cupcakes
- Beat the lemon zest into the butter until fully combined. Then beat in the sugar until light and creamy.
- Beat the egg and gradually add it to the mixture, beating well between each addition.
- Sift the flours together and add them to the mixture. Mix slowly until a ball of dough is formed. Tip the dough out onto a floured surface and knead it very briefly to bring it all together.
- Roll out the dough to a 5mm (1/4") thickness and transfer it to a flat baking tray. Refrigerate the dough for at least one hour.
- Line a second baking tray with parchment paper. Remove the dough from the fridge and cut out as many biscuits as possible using the heart-shaped cookie cutter. Transfer the biscuits to the lined tray, leaving at least 3cm (11/8") between them. Refrigerate the biscuits for a further 30 minutes.
- Preheat the oven to 180˚C (350˚F/ Gas Mark 4). Bake the biscuits in the middle of the oven for approximately 10 minutes, or until the biscuits are golden brown and beginning to colour around the edges.
- Leave the biscuits to cool completely on a wire rack before decorating.
- Sift the royal icing into the bowl of a stand mixer and add 85ml (24/5fl oz) of cooled, boiled water. Beat the icing on the slowest speed for between 5–10 minutes until it is very pale in colour.
- Pour the royal icing into a wide, shallow bowl. The opening needs to be big enough to easily fit one of the biscuits.
- Dip the tip of a cocktail stick into the Rose liquid food colour and swirl it into the royal icing, moving it around to create a marbled pattern (A). Repeat this process with the Cyclamen (Ruby) liquid food colour, using this more sparingly to create some darker areas (B).
- Hold the first biscuit upside down by the edges and dip the surface into the icing (C). Quickly flip the biscuit over to reveal the marbled pattern (D). Use the side of a cocktail stick to scrape off any excess royal icing around the edge of the biscuit to create a clean edge (E).
- Set the biscuit aside to dry on a flat surface for approximately four hours.
- Repeat steps 4–5 to ice all the biscuits. You may need to re-swirl the icing or add a little more liquid food colour, as necessary, between biscuits.
- Mix some Rose Gold lustre dust with a little clear alcohol, e.g. vodka or gin, to make a paint.
- Use a no. 1 paintbrush to paint fine lines of rose gold along some of the lines in the marbled royal icing (F). Set the biscuits aside until dry.