Really weird cake baking day. Doing a 14" tier and baked it in 2 batches. Both have come out perfect and even couldn't be better... moved on to the 12" doing same method (baking 2 layers separately) yet the first one has come out with cracks all over the top. I just don't understand it. Same mix, same method, same oven temp, bake even strips!

Only thing that is different is that the tin i'm using for the 12" is the multi size pan whereas the 14" was a standard 14" heavy duty tin. Could this be the problem you think? really frustrating

Could be... sounds like it's overbaked. I'd try lowering the oven temp.

actually just to add I've baked another 2 cakes, same method but the heavy duty tins and they are perfect too no huge cracks. its definitely that silverwood multi pan - that can go in the cupboard and only come out for multi cakes!!