1/2 tsp Saffron threads
200g caster sugar
630g plain flour
1 tsp baking powder
Salt to taste
1. Preheat oven to 180C/gas 4. Spread pistachios on a tray and bake for 5 minutes. Remove and leave to cool.
2. Soak the saffron in 2 tbsp boiling water. In an electric mixer, beat the butter until light and fluffy. With the mixer running, gradually add the eggs, sugar, saffron threads and soaking water; mix until creamed. Add the flour, baking powder and salt. Mix the dough until smooth. Using a wooden spoon, stir in the pistachios.
3. Line and grease a large tray or 2 smaller ones and role your biscotti into long logs about 2 cm high; you can make it wide for larger biscotti or thin for smaller ones. Bake for 30 minutes or until golden. Let the logs cool for 5 minutes then place on a cutting board. Diagonally slice each log into 2cm-thick pieces. Place back on the tray, cut-sides up, and bake for 5 minutes, or until golden. Turn them over and bake for another 5 minutes. When cooked, allow to cool then store in an airtight container.