Berlinerkranser cookies (Norwegian butter cookies)

Makes about 25

2 hard-boiled eggs 2 eggs, separated 250g unsalted butter, at room temperature 125g caster sugar 1 tsp vanilla paste 340g plain flour pearl sugar

Remove the yolks from the hard-boiled eggs and crumble them into a bowl. Add the raw egg yolks and beat well together. Place the butter, sugar and vanilla paste in another large bowl, or food processor, if you are using one, and beat until pale and fluffy. Beat in the yolk mixture, and then the flour. Chill the dough for 1 hour. Heat the oven to 180°C and line two baking sheets with baking parchment. Break off walnut-sized pieces of dough and roll them, on a lightly floured surface, into sausages, about 1½cm thick and 12cm long. Form them into wreath shapes, with their ends overlapping, and place them on the baking sheets 2cm apart. Brush with egg white and sprinkle lightly with pearl sugar. Bake for 10-12 minutes until golden.