Stem ginger cookie sandwiches

Put the flour, bicarbonate of soda and sea salt into a large bowl and stir to combine. In another large bowl, beat the butter and sugars using electric beaters until smooth and creamy. Add in the flour mixture and the stem ginger and, on a slow speed, mix until just combined and forming clumps. Tip the mixture out onto the worksurface and use your hands to bring together into a uniform dough. Halve the dough equally and form each into logs about 5cm in diameter. Wrap in clingfilm and chill for at least 4 hours until firm.

To make the caramelised white chocolate, heat the oven to 120C/fan 100C/gas ½. Break the chocolate into chunks and put onto a rimmed non-stick baking tray and bake for 1-1¹/2 hours or until a rich caramel colour. While baking, the chocolate needs to be stirred every 10-15 minutes to prevent it catching on the baking tray and burning. Make sure you give the chocolate a really good stir and scrape it off the bottom of the tray. The chocolate will go a little grainy during baking but will become smooth and creamy when stirred. Sprinkle with sea salt and pour onto a new baking-paper-lined tray and leave to set.

Heat the oven to 180C/fan 160C/gas 4 and line 2 baking trays with baking paper or silicone baking mats. Use a sharp knife to cut the cookies into ¹/2cm-thick discs. Put the cookies onto the baking trays, leaving a 2cm gap between each as they will spread a little as they bake. Bake for 11-12 minutes or until lightly browned around the edges. Allow the cookies to cool on the trays for 10 minutes before transferring to a wire rack to cool.

For the ganache, cut the hardened caramelised chocolate into small pieces and put into a small bowl. Put the cream into a small saucepan and bring gently to a simmer. Pour the cream over the chocolate and allow to sit for a few minutes before stirring to form a silky smooth ganache. Chill until thickened to a pipeable consistency. Spoon or pipe a small amount of the ganache on the bottom of half of the cookies and sandwich with a second. Put aside until the ganache has fully set. These will keep in an airtight container for 3 days.