250 g unsalted butter
130 g castor sugar
2 eggs
130 g plain yoghurt or sour cream
260 g all-purpose flour
¼ tsp salt
¾ tsp baking soda
2 cm fresh ginger (thinly shredded)
grated zest of one lemon
100 g candied ginger (chopped)
1 tsp ground ginger
150 g candied orange peel