Mix the flour, baking powder, spice, ground almonds and lemon rind together in a bowl.
Beat the butter and sugar together in another bowl until pale and creamy. Gradually mix in alternate spoonfuls of beaten egg and flour mixture until all has been added and the mixture is smooth. Stir in the dried fruit and the lemon juice.
Spoon the mixture into a 20 cm (8 inch) deep round cake tin lined base and sides with nonstick baking paper. Spread the surface level and arrange the almonds in rings over the top. Bake in a preheated oven, 160°C (325°F), Gas Mark 3, for 1¾ –2 hours until a deep brown and a skewer inserted into the centre comes out clean. Check the cake after 1 hour and cover loosely with foil if the almonds look as though they are going to overbrown.
Leave to cool in the tin for 15 minutes then loosen the edges, turn out on to a wire rack and peel off the lining paper. Leave to cool completely. Store in an airtight tin for up to 1 week.