Scandinavians love to make these cookies at Christmas time but they will go down well any time of year.

375g flour
1 tsp baking powder
1 tsp lemon zest
125g brown sugar
250 cold butter, cut into small pieces
1 egg, beaten

Topping: 
Mix 2 tsp cinnamon and 50g demerara or granulated sugar in a small bowl
1 egg, beaten

Sift the flour and baking powder into a large bowl. Mix in zest and sugar then rub in butter until dough resembles coarse breadcrumbs. Mix in egg and knead on a floured surface for a couple of minutes until smooth. Wrap in cling film and refrigerate for at least an hour or overnight.
Preheat oven to 200C. Line 2 baking tray with baking paper.
Sprinkle the dough with flour and place between 2 sheets of baking paper. Roll out to 4-5mm thick, cut into shapes and place on your baking trays spaced apart. Brush the top of each cookie with egg wash and sprinkle with cinnamon mix.
Bake for 8-10 min, rotating the trays halfway through. Watch carefully as they can brown quickly.
Transfer to a wire rack to cool.