Oscar Mayer is throwing its most famous vehicle a birthday party, marking 90 years of the Wienermobile with a celebratory Wiener Cake made in collaboration with Milk Bar. The tribute honors an icon that first took to America's roads in 1936 and has been a fixture of the national landscape ever since.The centerpiece of the build is its two-tier structure, which arranges delicious Oscar Mayer hot dogs around Milk Bar's number-one best-selling signature Birthday Cake. That base layer does the heavy lifting on the sweet side, bringing the bakery's established flavor profile into a format designed to read as a proper birthday centerpiece rather than a novelty. The hot dogs, meanwhile, supply the savory contrast, turning the pairing into the kind of sweet-and-savory combination the brand pitches as a dessert to relish.The detailing is where the tribute sharpens. The cake is dusted with "ketchup and mustard" confetti sprinkles, a color cue that maps the classic condiment palette directly onto the dessert without relying on the condiments themselves. Topping the whole thing is a commemorative custom Wienermobile cake topper, the finishing element that ties the build explicitly to the 90th-birthday occasion and the vehicle it honors.Taken as a whole, the Wiener Cake is a purpose-built celebration piece rather than an off-the-shelf bake. Every component, from the tiered arrangement of franks to the condiment-coded sprinkles and the vehicle topper, is calibrated around a single milestone, giving Oscar Mayer a physical centerpiece as distinctive as the Wienermobile itself. It is a fittingly unexpected setting for an Oscar Mayer hot dog, and a literal reading of the brand's birthday-tribute brief.For nine decades, the 27-foot hot dog on wheels has been one of the country's most recognizable brand symbols, turning up at the moments that define American life. Oscar Mayer traces its presence across parades, road trips and tailgates as well as graduations, weddings and, per the brand, even a professional race, a résumé that has cemented the Wienermobile in the national zeitgeist. Over the years it has also fielded tens of thousands of requests from fans hoping for a visit, a measure of the affection that has kept it culturally relevant far longer than most marketing creations survive.The Oscar Mayer Wiener Cake is available at select Milk Bar locations in New York, Los Angeles and Chicago from Friday, July 31 through Sunday, August 2, while supplies last.