Before we even get into the issue of "what is crumb cake, anyway?" I'd like to address why, exactly, I ought to be considered an authority on the subject. In my opinion, of course.
First off, I was born and raised by the Jersey shore.
This is part of what you could consider the "crumb cake belt", extending into New York state to the North and down as far as the mid-Atlantic to the south. To the best of my knowledge, though, the New York metro area and about an hour outside of it is really where crumb cake is a prime time food.
I have experienced a lot of crumb cake in my time.
From the time I was able to eat solids, it was a favorite of mine as I grew up by the Jersey shore; the square box of Entenmann's crumb cake was a constant in our house, and whenever I had the opportunity to get a treat at the bakery or a deli, crumb cake was always my pick. For me, crumb cake has always been one of those foods, that like pizza, "even when it's bad, it's still good."
I've tried it all: artisan versions, commercially produced versions, bakery versions, homemade ones. And with nearly 33 years of crumb cake eating under my belt, I'd like to offer some opinions and thoughts on the stuff.
Crumb cake in America
If I were to make an educated guess on the history of crumb cake, it would be this.
What we know today as crumb cake is most likely the adaptation of coffee cake recipes by German bakers who came to America. The cake does bear a passing resemblance to many of the streusel topped kuchen recipes, a popular coffee-friendly cake from Germany.
To further my conjecture, I would guess that stateside bakers responded to the fact that everyone loves crumb by adding more to theirs, thus making everyone come back for more. As we all know, a lot of the NYC deli treats (black and white cookies are a good example) are often impressive in scale; if some is good, more is better. Today, many crumb cakes boast as much as a 50-50 ratio of crumb to cake. We live in a blessed time.
A regional treat
Curiously, while crumb cake is delicious regardless of your geography, it seems to be available primarily on the east coast, with a particular concentration in the New York metro area. In general, from New York city out to commuter areas is going to be the epicenter.
As a result of the regional aspect, many people further away have no idea what crumb cake actually is or should be. I remember in Seattle, people would think that a coffee cake with a streusel topping was a crumb cake. Sometimes, bakeries would even label it as such, adding to the confusion.
So here, let me show you in pictures a review of what crumb cake is and is not.
What crumb cake is
In a world full of cakes that have crumbs, defining true crumb cake can sometimes be difficult. So let me illustrate some examples of what crumb cake is.
This is crumb cake. Note the lightly yellow-hued cake. It is not to be confused with yellow cake, which is sponge-like and airy. There should be a certain fluffiness to the cake, but it needs to be sturdy enough to be weight bearing, because as you may have noticed, there is a rather top-heavy coating of fat brown sugar crumbs. However, it is not as firm as pound cake; it has a little give.
As for the crumb, this is important: it is not a solid layer of brown sugar, but a collection of fat brown sugar clusters.
In contemporary times, it is my belief that crumb cake should be at the very least 1/3 crumb, preferably 1/2 crumb to cake. But less than 1/3 and it's not crumb cake, it's cake with a crumb topping.
If you are worried about adding too much crumb, don't be. As you can see from the above, even a 9/10 crumb to 1/10 cake ratio is just fine.
Crumb cake can be purchased in a few places: prominently at delicatessens, where it may be individually wrapped in plastic. It can also be found at bakeries and bagel joints. It is not necessarily a fancy food, so you should be wary of fancy establishments who try to take a unique spin on crumb cake.
What crumb cake is definitely not
I want to say from the get-go that it's very possible for non-crumb cakes to be delicious. However, tastiness aside, none of the below cakes are crumb cake, and should not be referred to as such. If I asked for a slice of crumb cake and one of these were delivered, I would definitely have words with the baker about their terminology.
Things called "coffee cake" with crumbs on top. Still not crumb cake.
Crumb topped bar cookies. Tasty, but not crumb cake. They have a cookie base, not cake, and a more dense, cookie-like crumb. Not crumb cake. Bar cookies. Got it?
Desserts with crumbs on top. Even if they are fat crumbs, like on this apple crisp, they are not crumb cake.
Almost but not quite crumb cake (in CakeSpy's opinion)
This is a coffee cake, not a proper crumb cake. The brown sugar swirl hidden inside is delightful, but it doesn't fully detract from the fact that there is 9/10 cake and 1/10 crumb going on here. The crumbs are too small; they aren't tightly packed or large enough. No.
Here is a fine example of a cake that almost, but not quite, classifies as crumb cake. While the ingredients are right, the ratio is off: it's more about the cake than the crumb. And speaking of the crumb, that's a problem, too: it's more like a thin layer of brown sugar topping rather than an assemblage of crumbs. This particular one tasted great, but lacked the satisfaction of crumbs the size of walnuts which you could pick off and enjoy.
Variations can be all right
Crumb cake is allowed to come in different variations and flavors. In New York delis, you'll see raspberry crumb cake (a thin layer of raspberry lives between the crumb and the cake), chocolate (the cake is marbled or two-tone and there is a chocolate ribbon on top), and a handful of other flavors. It is OK to add flavors to crumb cake. What is not ok, however, is to alter the architecture of the crumb top.
The crumb-heavy top is a constant, and must remain consistent.
As for the confectioners' sugar, I'm not a stickler. If they put a drizzle of glaze on top instead, I am fine with that.
What makes a good crumb cake
Here's a quick guide to the characteristics of a fine crumb cake:
- Ratio. Lots of crumb. No more than 2/3 cake.
- The perfect cake. Fluffy, but not spongey. Rich, but not pound cake.
- Salt. You have to have salt added to the crumbs. It makes them irresistible.
- Fat crumbs, presence of. The crumbs can be varied in size, but each slice should have at least one or two very fat crumbs.
- Coffee. Not as in you have to drink coffee with the cake (although that's quite nice) but as an indicator of the time of day best for eating crumb cake. It's the morning. Coffee time, and a cake that is not coffee cake, but crumb cake. If you have this cake for breakfast, it means you can still have dessert later!
Hey, if you love crumb cake, you may be interested in these recipes of mine: