You know the saying: Never trust anyone who doesn't like a good crumb topping. Okay…that's not actually a saying. But as far as we're concerned, the buttery, sugary layer on top of coffee cakes, crumbles, and fruit crisps is the best part. (In fact, associate food editor Claire Saffitz likes it so much, she'll ask co-workers to split slices horizontally, so she gets the entire top half.) Claire, we hear you. These elements are a must in mastering the art of a perfect crumb topping for any cake…or, hey, just for snacking.
It's all in the name: Chocolate-Rye Crumb Cake. Photo: Peden + Munk
The Formula
Cold Butter + Flour + Sugar + Spices + Salt + Optional Oats, Nuts, and Seeds
Learn this. Know this. Use this. Love this.
Form a Solid Mass, Then Crumble
Saffitz recalls the moment she realized what made a crumb topping successful. "Most people combine butter and the flour, sugar, and spices in a bowl, then mix with a spoon. There's always some dry, sandy-textured "silt" at the bottom of the bowl, which either gets tossed or turns into dry, over-baked "silt" on top of the cake. To make a better crumb topping, combine the ingredients with your hands and tweak the proportions until the mixture forms one solid mass. "It should be wet enough that your hand leaves an imprint in it after squeezing," explains Saffitz. In recipe lingo, look for terms like, "until no dry spots remain." That silt is a dry spot! The "crumbs" come from breaking apart that mass into irregular-shaped pieces and scattering them over the top of the cake.
Unfortunately, there is no hard-and-fast formula for a perfect crumb topping. That's because the amount of butter needed will change depending on the other ingredients: Whole wheat flour will absorb more fat than white, and adding oats, nuts, and seeds, also requires more butter. Just keep tweaking the ratio until your ingredients form that moist, dense mass.
Cold Butter Is Key
A well-made crumb should be firm yet tender, and chewy, with big chunks—like granola. The best way to achieve this is to use cold cubed butter. Using room-temperature or melted butter will cause the topping to spread out and flatten when it bakes, rather than standing pert and perky.
Just Say No to Baking Powder
Leaveners like baking powder and soda make baked goods light and airy—an excellent quality in cake. But when it comes to the crumb topping, we're all about density. The topping should have a nice amount of give under your teeth when you bite into it.
