Didn't Buffy say something about *baking a cake* (as in like she is the unready cake for him) to Angel when he gave her the amulet at the cementery in season 7 right before the last fight against *The First*? She gave him hope that - maybe somewhere in the future - they could be together.
So Drusilla with her *listen to the stars* has mistaken that picture in her mind and try to *bake the cake* for her *daddy dearest*, so he can be happy again?
Yes, sure. That would be typical Dru.