Why do my cakes sink in the middle?

[redwallday]

It's driving me insane! For instance last night I made an 8 inch square sponge cake. I used 6 eggs and 12 oz of everything else. It looked like too mixture so I took some away and made 12 cupcakes with it. The rest I put in the tin and put in the oven. All was well until near the end when it just collapsed in the middle. I didn't open the oven it just collapsed on its own. Ive had problems with this before but thought we had cracked it as last few have been perfect! Obviously not :( I don't know what I'm doing wrong!

Too much air, ingredients need to be at room temp and use correct oven temp!

How did you mix it?

I've got a Kenwood Chef. I creamed the butter and sugar first then added the egg with a little flour each time. My oven was set at 180oc. I've got 2 oven thermometers in there and they were both saying different things! One was high at 190 and one was about 170 (very frustrating!). :(

And yes everything was at room temp

Did you use baking powder? I'm sure Mary Berry said on GBBO that its a baking powder thing - either too much or too little.

Sorry for being vague and unhelpful, but it rings a bell.

Overbeaten and/or oven too hot.

Oddly enough outfoxed the same thing happened to me last sun, i made 3 sponges in differe t colours, first 2 fine, 3rd one my phone went while mixing , i use a mixer also, so things didnt get my full attention they deserved, put it into the oven ad previous 2 only to find near the end of cooking without opening any doors right in front of my eyes the bloody thing sank, was not impressed.

Try mixing it in a bowl with a wooden spoon and see if its better. You're less likely to over mix it. If it works you know that's the problem and then you can experiment with turning your kenwood off earlier.

Yes I added baking powder. I'm never really sure how much to add!! How much would you say for that size tin? Also what size mixture too as I said before it ended up looking too much to me. Thanks for your help everyone!

For 8inch tin buts thats round for me and usually square is more, i normally do 8 of everything and half tsp of baking powder if thats any help?.

How much baking powder did you add and what flour was already in it? Too much baking powder definitely makes things collapse.

You have to be careful not to knock the oven when the cake is in.

I think I used about a tablespoon of baking powder! Too much?

Oh and it's self raising flour.

That sounds like way too much. Generally I don't add baking powder if I am using SR flour.

As a general rule I use 1 teaspoon of BP per cup of flour. But SR flour has BP added already do you don't need to use it.

That's def too much raising agent. You don't really need to add any if using SR flour, unless the flour is old, or it's a special recipe. So all those eggs + SR flour + baking powder = a big initial rise with the heat of the oven, that could not then be supported, hence the collapse.

Definitely the baking powder! A tsp would be OK to give SR some oomph but a tbsp is way too much.

Yep, culprit identified. Try it without any baking powder if you're using SR flour, then maybe add a bit if you want it to rise more next time.

You guys are saints! I will try without BP tomorrow and report back. If this fixes the problem I may be inclined to send you all gift hampers!

I just baked a cake using Mary Berry's all in one Victoria Sponge.It sunk ,looks like a crater in the middle.I have used this recipe loads of times over the years with no problems,but lately I have been having them.I know self raising flour already has baking powder in it,but this recipe calls for 2level tsp of bp