焼ける and 焼く: baked bread and the act of baking
Compare baking bread or grilling fish with the cooked result, and distinguish potential 焼ける from uses involving sun exposure.
The cooking action and checking readiness
オーブンでパンを焼いています。 says that someone is baking bread in the oven. 焼く, read やく, has the te-form 焼いて, with パンを as the item being cooked.
パンが焼けました。 can announce that the bread is baked and ready. 焼ける, read やける, presents the result from the food's side.
Cooked versus burnt
魚は焼けましたが、焦げてはいません。 says that the fish is cooked but not burnt. Do not always translate 焼ける in a cooking context as charring.
表面だけでなく、中まで焼けているか確認してください。 asks someone to check whether it is cooked through, not just on the surface. 中まで specifies the required extent of cooking.
Ability and sun exposure
このオーブンなら、パンを四つ同時に焼けます。 means that this oven can bake four pieces of bread at once. Here 焼ける is the potential form of 焼く.
海で一日過ごして、肌が焼けました。 says that a day at the seaside affected the skin through sun exposure. It concerns tanning or sunburn, not cooking food.
Does 焼けます in このオーブンならパンを四つ同時に焼けます report that the bread is already ready?
Show the answer and why
No. It expresses the oven's capacity to bake four pieces at once. Distinguish this potential form from パンが焼けました, which can report readiness.