Technically, if she's REALLY "pulling a Cookie Monster", she can just throw it in her mouth and crush the cookies to crumbs and just let them all spill out...
But you know fanon fisiks - if the author wants dolls to eat cookies, dolls can eat cookies.
Trick or Treat!!I'll gobble you up if you don't hand over candy!!What Marisa? Can't you come in a little quieter?Also, why are you wearing kitty ears and fangs?Don't you like these kind of clothes? Meooow♡What? You're being stiff.I came to get some candy because it's Halloween!★Candy huh? Well, we have some but...
Shanghai, can you go grab some?Ohh! I knew you would, Alice!Shang-haaai!Ey, what did you make?Pumpkin cookies.Thank you.Hehehe♥All right. These are the cookies...Cat ears!Oof.Ack! Hey! Why... did you eat it!!?Blush~On second thought, I'll take that back!!I take that back!!Ohh, what is this? You're pretty well prepared. Heh, did you make them for me?Shang-haai♥♥I bet Alice's cookies will be delicious.Oh! Thanks Alice!Weren't you supposed to give that to me?AaAAaahNomLooks like we ran out of cookies.That's cruel Alice. Did I do something...?Hmm... I'd rather have you try it. After all, isn't it "Trick or Treat?"ZuuuunIn other words, ...I want the one that's not candy...♥Finally got it.*stroke stroke*I won't do it!! I repeat, I WONT DO IT!So you won't tease me?PlikWhat!?Aaaahh!!!