Preheat the oven to 160°C/140°C fan/325°F/gas mark 3. Grease a 20 cm/8 in round, approx 9 cm/3 ½ in deep cake tin and line the base and sides with a double layer of baking parchment, making sure that it comes above the top of the tin by a couple of cm/1 inch.
Whisk together the butter and sugar with an electric mixer until smooth and creamy then whisk in the marmalade and orange zest.
Add the flour, ground almonds, baking powder, mixed spice, milk and a pinch of salt and mix to form a smooth, thick batter. Don't over-beat it, just mix until it is fully combined then stop.
Add the dried fruit and fold through.
Transfer the batter to the prepared tin and spread it level. Use the back of a wet spoon to smooth the top.
Arrange the blanched almonds in circles on top of the cake. Press them only very lightly into the batter.
Bake the cake for about 2 hours until a skewer inserted into the centre comes out clean. If the top of the cake starts to get too dark before it is cooked then you can loosely cover it with a piece of tin foil. Do not open the oven door until the cake has been baking for at least 1 ½ hours however.
Leave the cake to cool in the tin completely then turn out and store in an airtight container.