A model number may help others help you.

Many units have a thermal cut-off on the back of the oven that can blow shutting down the elements.

Here is a manual for a Frigidaire manual.
http://frigidaireservicetips.com/pdfs/481_18.pdf

It does have a safety thermostat (see page 37).

Please post your model number and then with luck we will be able to find a wiring diagram for your model and hopefully narrow down the possible causes of your problem.

Here are your parts. Could not find a CC following is CB but should be a real close match.
Replacement parts for FRIGIDAIRE PLEB30T9FCB Frigidaire/walloven | AppliancePartsPros.com

Here is a wiring diagram
http://manuals.frigidaire.com/prodinfo_pdf/Lassomption/318046123.pdf

In the wiring diagram it shows the cut-outs in the common wire to the elements so it will kill both elements.

If you look at the parts (Item 119 in sections 2 and 3) you will see the thermal cut-outs.
If you click on the parts picture, you will get a better view of it.
It looks like it is re-settable re: the square red center is probably a pop up.

Since getting at is a pain I would check at the relay board.
Bake or Broil to DLB connectors should read 10 to 20 ohms.
If both readings are open (infinite ohms), you know the thermal cutoff has tripped or a wire has burned out.
Be sure to remove power from the unit when working on it!!!

You may also want to check the temperature probe, just in case it caused an over heating.
Here is a good link on how to do that.
http://www.applianceaid.com/elecrange.html

The control board also could have caused it to overheat.

I am not sure if the cooling fan comes on during self clean. If it is supposed to then I would also check it.

The cutoff is probably going to be a pain to get at, perhaps the following will held
http://manuals.frigidaire.com/prodinfo_pdf/Lassomption/318201514.pdf

I would get a oven thermometer and check that the set and actual oven temperatures are close.

Here is the timer guide. It shows how to adjust the temperature. See page 18.
If this is/was a problem you probably would have seen that the oven always seemed hot and it baked faster than the recipes said.
http://manuals.frigidaire.com/prodinfo_pdf/Lassomption/318200138.pdf

And one last thing if everything looks OK and you were using a long self clean cycle. I would clean the oven more often using a shorter self clean.