Malted Oat Shortbread Sandwich Biscuits

Preheat your oven to 180°C (160°C fan/gas 4). Spread the porridge oats evenly over a baking sheet and toast in the oven for 8-10 minutes, stirring halfway through, until they are golden and fragrant. Remove from the oven and allow them to cool completely.

In a food processor, combine the plain flour, cornflour, and golden caster sugar. Pulse a few times to mix. Add the chilled, cubed butter and pulse until the mixture resembles fine breadcrumbs. Add the egg yolks and pulse again until the dough is moist and starts to clump together. If the mixture feels too dry, add a tiny splash of water.

Transfer the dough onto a clean work surface and scatter the cooled toasted oats over the top. Gently work the oats into the dough by hand until evenly distributed, then form the dough into a ball. Divide the dough in half and shape each piece into a rough square. Wrap tightly in baking parchment and chill in the fridge for at least 1 hour.

Once chilled, preheat the oven again to 180°C (160°C fan/gas 4). Roll each piece of dough out between two sheets of parchment paper into a 30 x 30cm square. Trim the edges to make them neat. Cut the dough vertically into 3cm wide strips, then cut horizontally to create 7cm-long rectangular biscuits. You should end up with approximately 50 individual biscuits.