Answer:
PERFECTLY
Step-by-step explanation:
Adverbs are words that modify, describe or give further detail of adjectives, verb or other adverbs. They give information of when, where, how, in what way, in what degree, to what extend or why something happens, and many of them has the "-ly" ending. In the sentence, "perfectly" is the adverb because it modifies the verb "bakes" by providing information about the way (how) the pastry chef bakes pies.