When the annual What the Fluff Festival rolls into Union Square on Sept. 23, it’s an extra-special occasion: This year the Somerville-bred gooey goodness celebrates its 100th anniversary since resident Archibald Query whipped up the mixture of sugar, corn syrup, dried egg whites and vanilla. A couple of fellas by the names of H. Allen Durkee and Fred Mower purchased the recipe in 1920 for $500, and the same families have been making the same recipe in the same town since the ’50s, getting into the radio business and dreaming up Marshmallow Treats with Rice Krispies along the way. At this week’s 12th installment of the festival, get in on everything from Fluff jousting to marshmallow tosses—or, get your sticky fix around town with some of these sips and snacks.

Gather chef Dennis Wilson’s Fluffernutter stuffed French toast ($15) stacks crunchy Frosted Flakes-crusted challah bread with layers of Fluff, and tops it all off with berries. And the brunch menu will soon feature another Fluff-centric addition with a new Waffle Sunday special.

At Gracie’s Ice Cream, the signature Fluff cone is smothered in the marshmallowy treat before being torched, but the Fluff options at the Union Square shop don’t end there. Fill up on flavors like Fluffernutterbutter, which packs Nutter Butter cookies and Fluff into peanut butter ice cream, or check out the new raspberry-flavored Pink and Fluffy.

The Gallows’ lone dessert option holds its own. The Stoner’s Delight ($8) trifle features a bruleed heap of bananas, peanut butter mousse, chocolate ganache and Fluff—a solid nightcap that owner Rebecca Roth Gullo calls the ultimate salty and sweet ending.

Hojoko blends two rums and pineapple for its frozen piña colada ($12) that’s served in a frosted mug and topped with a torched ’mallow. Fluff’s folded into the cocktail’s coconut milk for a little extra sweetness, which pairs nicely with the spicy kick of the menu’s tuna burger.

Rosebud American Kitchen & Bar pays tribute to its diner car past with Milkshake Monday specials, and one frequent suspect, the Fluffernutter ($13), returns to the lineup to celebrate the Fluff fest. The bourbon-spiked ice cream concoction includes Fluff and peanut butter and is trimmed with whipped cream and a mini sandwich.