Is there a sensor that is equivalent to a dry toothpick?
The best approach for determining when baked goods are done is to put a thermocouple probe in the item being baked. The basic idea is bake until the probe reports that the item has reached its terminal temperature. Different baked goods may have different terminal temperatures. Bread, as one example, may be done at around 190F. This can be varied based on personal taste and experience.

Thermocouple probes and cables are available that can provide good service life at bake oven temperatures. The probe cable, which is quite thin, can be routed out the oven door and to an electronic device which can read out the probe temperature.