Take a look at the sentence again:
Jeremiah likes to put peanut butter on his pancakes instead of
syrup, the smell is appealing, but I wouldn't
want to eat anything so sticky that early in the morning.
For a sentence to be fused, you must have two complete sentences run together with no punctuation. In the example above, a comma joins the two sentences. Jeremiah likes to put peanut butter on his pancakes instead of syrup is one sentence. The smell is appealing is the second sentence. Thus, the error is a comma splice.
Remember that both comma splices and fused sentences are major errors. They make your reader think that you cannot write a correct sentence. Because the sentence is the most basic building block of a piece of writing, comma splices and fused sentences make you look like an amateur!
To fix the problem above, you could put a period after syrup and capitalize the T in the.