A good crumb cake—like the ones I grew up with in New Jersey—is top heavy. The simple vanilla cake supports a thick second story of tender, cinnamon-laced, brown sugar streusel and a snowcap of powdered sugar. At New Jersey bakeries, crumb cake is typically sold by the rectangular slice directly from the sheet pan; at delis, you’ll often find slices wrapped individually in plastic (environmentally distressing, but this does create, in my opinion, the perfect extra-moist texture). For those who do not live close enough to purchase such a treat on a lazy weekend morning, I set out on a quest to develop a recipe for the closest possible iteration that doesn’t use any special equipment or hard-to-find ingredients (you’re welcome).
Crumb cake’s presumed predecessor is German streuselkuchen, a yeasted cake topped with a modest layer of crunchy streusel. As Americans love to do everything bigger, many of today’s crumb cakes have evolved into nearly a 1:1 ratio of crumb to cake—and many are even more generous with the crumb. Some add in a layer of jam or flavor the cake with chocolate or warm spices as they do at Park Ridge bakery Just Crumb Cake. But across the board, the topping isn’t the same crispy-crumbly streusel you’d find on a berry crumble or pie: It’s thick and soft, with an almost cookie-dough-like texture. The general components needed are flour (more on which kind in a minute), sugar (mostly brown, sometimes a bit of granulated or powdered), and fat (significantly more than you’d expect), but there’s no consensus among bakers from there.
Carlo’s Bakery in Hoboken actually uses crumbled premade vanilla cake in their crumb topping, which reminds me a bit of the method used to make a cake pop. “If you go back to the old traditions of bakers, they never wasted anything,” Joe Faugno, head baker at Carlo’s Bakery, notes in a YouTube tutorial of their crumb cake recipe. “They figured a way to use up the leftover cake that they couldn’t serve to customers.” The crumbled cake is paddled in a stand mixer with softened butter, pastry flour, brown sugar, baking powder, and salt; then left to rest at room temperature for an hour to firm up. Using cold butter in the topping and/or chilling it before baking can help the crumbs hold their shape as the cake bakes. However, chilling the topping, especially when you’re not mixing it with tender cake crumbs, can make for a slightly dry end result.
So how does the crumb topping bake off in a neat layer but stay soft? Some say baking powder brings lift and tenderness; I found it added unnecessary crispness, where the goal was always to keep things moist. Other bakers swear that cake flour, even a DIY version with cornstarch and all-purpose, is crucial: Jessie Sheehan, author of Snackable Bakes, notes in her recipe for Extra Crumb Snacking Cake that “the softness of the crumb topping and tenderness of the cake owe everything to it.” Cook’s Illustrated Baking Book echoes this in its New York–Style Crumb Cake recipe (though they use melted butter in the topping instead of Sheehan’s cold cubed). I still found the most straightforward method—loads of melted butter dragged around with a fork into a mix of all-purpose flour, mostly dark brown and a smidge of granulated sugars, and plenty of salt, left to hydrate at room temperature while mixing up the cake—made a thick layer of soft, dense crumb. It’s best distributed in two batches to ensure distinct layers of cake and crumb, the first two thirds in small crumbs across the cake’s surface, the rest in larger pieces.
For the cake layer, you’ve got two options: yeasted dough (this version is sometimes called “crumb buns”) or a simple thick yellow cake batter. Many bakeries, like Carlo’s, use the former, as does B&W Bakery in Hackensack, which bills itself as “home of the famous heavy crumb cake”—but the rest of their recipe is a trade secret. While it may not pay homage to streuselkuchen origins, I prefer crumb cakes that follow the cake batter direction. I think the moist cake’s texture meshes better with the thick, soft crumb than shreddy yeasted dough does, with the added benefit of no time spent proofing. While I dabbled with adding cornstarch along with all-purpose flour to mimic cake flour per Sheehan and Cook’s Illustrated, I eventually found a perfectly tender cake was possible with solely all-purpose and plenty of fat (vegetable oil and sour cream). A thick batter was the key to ensuring the topping didn’t sink too deeply into the base.
Packaged snack cakes have also contributed much to the conversation about what makes an ideal crumb cake. Sheehan calls out Drake’s Coffee Cakes in her book’s recipe (the packaged cakes use palm and soybean oil; Sheehan’s cake is enriched with vegetable oil). Entenmann’s makes several variations: Its Classic Crumb Coffee Cake and New York Style Crumb Cake have nearly identical ingredients lists, including vegetable shortening and vegetable oil. The brand’s Butter French Crumb Cake (unsurprisingly) includes butter and vegetable oil. Strangely, the difference between Entenmann’s classic and New York versions is a taller cake, not a steeper mountain of crumb topping like you’d find in actual New York (and New Jersey!) bakeries and delis. All the more reason to make your own.
