Which is a compound sentence?

 - Her dog happily fetched his tennis ball from the muddy puddle and eagerly waited for her to throw it again.
 - I followed Sarah's recipe, but my chicken pot pie tasted nothing like hers.
The first sentence is the compound sentence. It is made up of two independent clauses joined by the coordinating conjunction but.
I followed Sarah's recipe, but my chicken pot pie tasted nothing like hers.