Triple-Decker Nut-Crazy Vanilla Cream Cookies
The Triple-Decker Nut-Crazy Vanilla Cream Cookies were a type of cookie baked by Spike.
He baked them for the Centennial Celebration, though he hate some of his own supply before the picnic. According to Pinkie Pie, the cookies were "delish" and praised him for his cooking skills.
In fanfiction
The cookies were referenced throughout In Memory Of, a fanfiction about the last days of Twilight Sparkle. As the fanfiction was written during the Weird age of Fanfiction, several aspects of pony lore wasn't established yet, or have major events transpired yet, so Twilight was still a librarian in her elder days.