Finnish Sugar Cookies
250g (9oz) plain flour
75g (2 1/2 oz) granulated sugar, plus more for the top
200g (7oz) butter, chopped
2 tablespoons finely grated unwaxed lemon zest
1 egg, lightly beaten
Sift the flour into a bowl and mix in the sugar, butter and lemon zest, first by rubbing with your fingers and then by mixing with a wooden spoon, until the dough is smooth and firm. Wrap in cling film and place in the refrigerator for one hour.
Preheat the oven to 190°C.
Now place the dough between two sheets of baking parchment and roll it out to a rectangle about 1.5cm thick. Remove the top layer of baking parchment.
Brush the dough with egg and dredge sugar densely on top. Carefully roll over it with a rolling pin, so the sugar is pressed slightly into the dough to make the crisp topping to these cookies. Cut into 3 x 2cm pieces, place them on baking trays lined with fresh sheets of baking parchment and bake for 15–18 minutes.
Leave to cool on a wire rack.
When they are completely cold, store them in an airtight container. They should keep for two to three weeks.
Source - Scandinavian Baking by Trine Hahnemann