Do I use the fan with circle around to bake cakes? Even my sponge cakes no more good-:)pls help I tried both lines plus fan. Also both lines alone. Also fan alone.. No difference. Iv been making for years in non thermal ovens and cakes wer perfectI'm renting this House so don't have the manual nor do I know the model but it's new and in the wall not with stove top.. It also has lights in the function buttons. You wil know