Pre-heat the oven to 180°C, 350°F, Gas Mark 4.
Sieve the flour, baking powder, Mixed Spice and sugar into a large bowl and mix well. Stir in the eggs and lemon zest. Knead together then add the cherries and pistachios.
Line 2 baking sheets with non-stick baking paper, then divide the dough into 4 even pieces. Roll each piece into a sausage about 30cm long. Place 2 onto each tray well spaced apart. Bake in the oven for 25-30 minutes until the dough is firm.
Remove from the oven and reduce the temperature to 140°F, 275°C, Gas Mark 1. Cut the dough into slices 1 cm thick. Lay flat onto the baking sheets. Bake for another 15 minutes, flip over and bake for a further 10 minutes on the opposite side. Allow to cool on a wire rack and dust with icing sugar.