I also had the problem of cake recipes which I had used very reliably for years in other ovens ( including those with a fan) ending up ruined. A friend suggested I put my sponge cakes into the oven BEFORE SWITCHING ON THE HEAT! I too found this beyond belief BUT it works! It does however take longer to cook. The main problem is that I cannot cook a succession of cakes as the cooker needs to cool between batches. As others have found, pastry and other types of cooking seem to be fine in a Teba oven. I am now going to eat a piece of freshly baked banana cake which has risen perfectly by starting the cooking from cold!
Anne Bainbridge, May 2012