Preheat the oven to 180℃ (160℃ fan)/350°F/gas mark 4. Grease the cake tin with butter or oil.
Prepare the peaches, peel, stone and cut the peaches into dice. Wash and dry the redcurrants and remove from the stems.
Beat the butter and sugar together until very pale and fluffy, then beat in the eggs one at a time, beating well after each addition. Add a tablespoon of the measured flour with the last egg to help prevent curdling.
Sift the remaining flour and baking powder into the bowl and fold in. Add the prepared fruit and ground almonds and gently fold in until combined.
Spoon into the prepared tin and level the top. Bake in the centre of the oven for about 1 hour or until springy to the touch and a skewer inserted into the centre comes out clean.
Allow to cool in the tin. To serve carefully transfer to a serving plate and sprinkle with icing sugar.