What Correctly punctuated fresh bread from the oven my mouth starts to drool at thought?

The sentence should be punctuated as follows:

Fresh bread from the oven—my mouth starts to drool at the thought!

The em dash (—) is used to set off a phrase that is essential to the meaning of the sentence but grammatically incomplete. In this case, the phrase "my mouth starts to drool at the thought" is essential to understanding why the speaker is talking about fresh bread from the oven. The exclamation point (!) is used to express strong emotion, in this case, the speaker's delight at the thought of fresh bread.