Preheat the oven to 190°C/375°F/Gas mark 5. Grease and line a 20cm/8in round springform cake tin.
Trim the aubergine and slice lengthways into slices about 5mm/1⁄4in thick. Put in a bowl, sprinkle liberally with salt, and set aside for 30 minutes to remove any bitter juices. Rinse well under cold running water, and drain.
Bring a saucepan of water to the boil, and blanch the aubergine for 1 minute. Drain and pat dry with kitchen paper.
Cook the pasta shapes in lightly salted boiling water until al dente. Drain well, and return to the saucepan. Add the soft cheese and allow it to melt over the pasta. Stir in the passata, Parmesan and oregano, and season with salt and pepper.
Arrange the aubergine over the bottom and sides of the cake tin, overlapping the slices and making sure that there are no gaps.
Pile the pasta mixture into the tin, packing down well, and sprinkle with the breadcrumbs. Bake in the oven for 20 minutes, then remove the tin from the oven and leave to stand for 15 minutes.
Loosen the cake around the edge with a palette knife or spatula, andrelease from the tin. Turn out the pasta cake, aubergine side uppermost,and serve hot.