I am having trouble with my 3" deep cakes. When I bake them at 350 degree, they will form bubbles on top then fall in the center. I am using bake even strips, I generally cook them around 1 hour, then they turn golden brown on top, however when I barely touch the top it is still jelly in the middle, then that is when it falls. How long should I cook a 14" 12" 10" and 8"?

Try a heating core or take a flower nail, grease and flour it and put it head down in the center of the pan. This draws heat to the center and will help the cake bake more evenly.

Also, try lowering your oven temp to 325 and bake a little longer. I never bake a cake at 350. More often then not, I bake at 300 and keep checking after the first 30 mins.

Try baking the bigger ones in a lower temperature, that might help. Other than that, there really isn't a universal time for baking cakes. It depends of every recipe.