Hi, there have been no changes to the eggs or baking powder. The oven does get serviced, and often it's not the whole bake thats effected. It is also cakes from different parts of the oven each time so I didn't think it was the oven. It does usually have this pattern to it though, or mainly in the centre. I have tried mixing the cakes more and less, but neither of these seem to have any impact either.
10/23/12 at 3:25am