From time to time my cupcakes do not rise or sink in the middle and spill over the liner.  I fill them 2/3 full and this has happened with different receipes.  Any idea why?

AHi,

Here's some foolproof advice that I've learned over quite some years... I always use my trusted friend - my ice cream scooper and it's worth investing in a decent one because it will always give you the perfect cupcake each and everytime which is harmonious and then you're also saving time by not having to correct the mistakes if that did happen again and then there's no wastage but just make sure that you cream your fats together first (butter and sugar) but what I think you did which is a very common mistake is by opening the oven too early or like half way through them baking which is how they usually sink in the middle but by using this tool it will eliminate any over spilling again, hope this helps, Jessiecakes x

Jessiecakes had a couple of interesting suggestions. Using an ice cream scoop for portion control helps keep products at a consistent size. But if your cupcakes don't rise, that's an entirely different problem. Make sure you have a good recipe and do not forget the leavener. Also, I know many people say not to open the oven door while baking, but I've not found it to be a problem. I owned an all scratch bakery and cafe and with all the thousands of products coming and going from my ovens, opening oven doors was a regular occurrence with no damaging effects.

Thanks.  You know come to think of it the two times I had problems was both quite a bit of red food color, do you think that may have had something to do with it?

ANo worries, anytime. If you add food coloring I.e sugarflair to your mixture it shouldn't make a difference, what I think is the problem is the recipe you're using. If you don't mind me asking which one do you use? x

Sunken cake usually is one of 2 issues (in most cases anyway, there are others but not common ones)

1) too much chemical leavener - baking powder, bicarb, etc. when there is too much it causes the cake to rise too fast and then because it can't support itself it collapses.

2) under baking, if they aren't properly baked through you have a similar problem, the cake cannot support itself so it collapses. The way I test cupcakes it to press on the top of them, if they bounce back with no problem then they are done!