Cut ginger into fine strips. Wash the currants, drain well and strip the berries from the panicles. Quarter pears, peel, remove core and dice flesh. Sprinkle with lemon juice.
Cream butter, sugar and ginger with the whisk of the hand mixer. Add the eggs one after the other and mix. Mix flour and baking powder and add to the butter mixture by the spoonful. Fold in fruit.
Put the dough into a greased and floured box form (11 x 30 cm), smooth it down and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for about 1 hour.
Let the cake rest in the mould for about 10 minutes, then turn out of the mould, let it cool down completely and dust with icing sugar.