This is a sudden problem but I know my measurements are right, it's recipes I've used before and oven temperature is tested. Could it be something is wrong with the flour or the butter?
Hi SRA. That’s so strange! I think butter temperature may have something to do with it. For pie dough, is your butter very cold when you cut it in? I have no idea why that would happen with cakes. Hoping you can resolve the problem. Good luck!
Have you changed brands/type of butter or flour recently?
Hi. Many different butter brands over the years but always the same flour. Butter is cold for pie crust and chilled before baking.
It could be your butter? I know I recently gotten very different results using two different types of what I thought were plain old American butter. One of them behaved normally, the other (again, nothing on the packaging indicated it was anything other than regular butter) warmed faster, felt softer, and creamed differently with sugar. Since you mentioned your oven is temperature tested that shouldn't be the problem. You could also try baking things on a tray to help with heat distribution: I placed my pie crust in its pan on a baking tray/sheet pan in oven when I had a temperamental oven. Hope you figure it out, this kind of knit-picky stuff is so tricky and frustrating!
Check and see if the butter you've been using has a higher fat content than butter you've used in the past. European butter and some higher-end American butter can be a few percent higher (~82-85%) than is common in American butter (~80%). The European-style stuff is great, but can sometimes weep out when used in a recipe developed with the slightly less rich butter common in the US.