Kitchen Large Electric Appliances - GE Oven - Broil element comes on during Bake cycle.

Attempting to bake but after a short period where only the bake element is heated, the broil element comes on and proceeds to burn the contents.

I've personally never ran into this. And I have dealt with a lot of ovens over the years in rentals. Some ovens are set up so some broil element heat always is there.

Is your broil element actually getting cherry red when this happens, when you only have it set to bake? If not, you might be fooled and have proper operation, and the oven control switch thermostat simply has gotten way out of calibration and needs a new one.

Some oven control switches are able to be calibrated about 25degrees, by turning a tiny screw on the switch, or adjusting the knob. Some knobs are adjustable, but many are not. You can tell by pulling the knob off the control switch and looking on the back side of the knob to see if there is a screw you can loosen and turn it.

But much more than 25 degrees off, and you need a new control switch. That is the switch that has the temperature numbers on it, and also attached to it is the sensing bulb - that long skinny rod that clips inside the oven compartment.

Does the oven have electronic controls? If so, during bake preheat, it cycles both the bake and broil elements alternately. After the oven is preheated it cycles only the bake element.