Last night I briefly left my bedroom to do a hair mask, and when I came back my dog was lying next to my phone

with nearly an entire cookie directly on top of it. Then she begged me for attention the rest of the night.
I can’t imagine where she found a cookie, and how she managed to get it through my house without me seeing it. Has she been hiding it for this special occasion?
Here’s the cookie in question. It looks like just the edges have been nibbled off.

(I did thank her many times for the gift)