I love cinnamon in almost anything, and tried working it into a biscuit recipe. This is what I came up with. Pine nuts are lightly toasted and make an interesting addition to these shortbread biscuits, which have a lovely cinnamon aroma.
Mix together the flour, icing sugar, salt and cinnamon. Tip in the cubed butter, and rub together until mixture resembles fine breadcrumbs. Add the egg yolk and combine until a solid ball of dough is formed.
Work in the chopped pine nuts. Roll dough into a log, approximately 3cm in diameter and 25cm long. Wrap in cling film and chill in the fridge for 2 hours, or up to 5 days if making ahead.
Preheat the oven to 170 C / Gas 3. Line a baking tray with baking parchment.
Once dough is chilled and solid, remove cling film. Slice into 5mm rounds and place on baking tray. Bake for 15 minutes, or until a light golden colour. Cool and store in an airtight container.