This is a sturdy everyday sort of chocolate cake, which you can make more or less luxurious by varying the quantity of add-ins, and by choosing dried fruit and nuts to suit your budget. I wasn't feeling very extravagent, so only added 50g of chopped chocolate and 50g of sweetened dried fruit (cherries, cranberries, strawberries and blueberries), but the cake would easily have taken double this amount. More common dried fruit, such as sultanas and raisins, would make the cake cheaper.
Good Food recipe for a 'lighter' lemon drizzle cake. I kept the quantities of grains, sugar, eggs, oil and yogurt the same, but instead of using 175g flour, 50g polenta and 50g ground almonds, I used 200g flour, 25g cocoa and 50g coarsely ground hazelnuts. Any trace of lemon was omitted, as well as the final soaking syrup. The chopped chocolate and dried fruit was stirred into the final batter. I whizzed the fruit a little in the mini-chopper, after grinding the nuts, to cut up any large pieces of fruit - the strawberries were quite large.
This wasn't a very rich chocolate cake, as befits an 'everyday' cake, but it was well-flavoured and moist and it was nice to chew on the juicy pieces of fruit, which aren't often added to chocolate cake. As I said earlier, adding more fruit and chocolate would make a more luxurious cake.