Answer:
The colon is correctly placed and necessary because the introductory text can stand alone.
Explanation:
Some of the uses of the colon include to introduce lists of anything (whether activities, people, objects, etc.), but it needs to be preceded by a complete thought, more specifically, of an introductory sentence that can stand alone.
"she bought several baking goods" is the introductory sentence of the items, and it is also a sentence that can stand alone because it expresses a complete thought.
If the introductory sentence ended with a preposition, for example ("she bought several baking goods like/such as"), the colon would not be necessary because such introductory sentence could not stand alone and still make sense.
