Preheat the oven to 180°C, fan 160°C, gas mark 4. Line 2 baking trays with non-stick baking paper.
Sieve the flour, baking powder, mixed spice and sugar into a large bowl and mix well. Stir in the eggs and lemon zest.
Bring the dough together, then add the cherries and pistachios and knead until evenly distributed.
Divide the dough into 4 even pieces, and 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°C, fan 120°C, gas mark 1.
Cut the dough into 1cm-thick slices and lay flat on 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, then dust with icing sugar before serving, or wrapping in gift bags or boxes, ready to give away.