I have just made this cake and all was going perfectly. However when I opened the oven door after the 20 minutes - the whole cake had flopped in the middle. When I turned it out the centres stuck to the pan. The cake otherwise looks and tastes delicious but I cannot serve it. The icing is delicious.
The exact same thing happened to me!! As the oven timer pinged both cakes dropped. I cut the middles out and turned it into a ring cake hahaha. But yes, it tastes great. Going to try again but look forward to an expert's answer here.
Check out Sarah's Cake Troubleshooting Guide...there may be some tips in there for you about why cake's sink.
Also don't forget to make sure your eggs and butter are all at room temperature, as if they are not they can cause your cake to sink too.
HI Yolande and Riette
Sorry that you've had some trouble with this! I find that there are usually a few reasons that this could have happened - which might sound frustrating as it's not a 100% clear answer, but it also gives you a really good idea of what might have gone wrong:
1. Too much raising agent (could not have measured absolutely accurately) OR it could also be because your raising agent is too old (test your baking powder by sprinkling a tsp into a glass of warm water, it should bubble if it is still fresh)
2. Over-mixing the cake batter
3. Oven door opened too early (even 20 mins can be too early depending on oven)
4. Oven not at correct temperature/not pre-heated long enough and so cake didn't cook for long enough to compensate for this (it can take up to 30 minutes for some ovens to reach the correct temperature, so this is where an oven thermometer comes in handy)
5. Cake sat on the counter for too long before going into the oven (up to 20 minutes or so is fine)
Please let me know how you get on!
Best baking wishes