How to Make a Texas Sheet Cake
If you've never had the pleasure, Texas sheet cake is a full slab of mellow chocolate cake that’s literally doused in hot fudge, then buried under an avalanche of toasted pecans. Baked in a half-sheet pan, it’s clearly designed to feed a crowd, but it keeps so well that a small family could nibble on it for a week. In short, it deserves a place in any baker's repertoire.
The sheet cake is based on buttermilk and natural cocoa powder, giving it a much lighter profile than the dark and earthy intensity of a traditional devil’s food. It’s a formula that's a little lean and acidic, which lets the fruitier character of chocolate shine through and makes the cake itself a fitting finale to a heavy meal. Think Texas barbecue, picnic tables loaded with mac and cheese, or fried chicken dinners.
Meanwhile, the frosting is closer to a glaze—milk, sugar, and more of that natural cocoa, boiled up into a sort of fudge, then poured over the cake as soon as it comes out of the oven. The hot cake soaks up the molten fudge like a sponge, and the result is a semi-dissolved layer of gooey cake sandwiched between fluffiness below and fudginess above.
It's a brilliant textural mash-up, especially once you factor in the crunch of pecans. Even better, the fudge layer seals up all the pores along the surface of the cake, protecting it from moisture loss. That gives it a great shelf life, so it’s a terrific make-ahead option for parties, potlucks, and picnics.
Because cocoa powder is the primary source of flavor in both the cake and the frosting, reaching for the good stuff will make a world of difference. When it comes to chocolate, fat is flavor, and virtually all supermarket cocoa powders are low-fat, which means they are, conversely, high in starch, giving them a dry and chalky nature.
Fortunately, high-quality natural cocoas are easy and affordable to buy online. For more information, read my guide to my top five brands of natural cocoa powder.
The short story is this—my favorite, Gerbs Natural Cocoa Powder, has over three times more cocoa butter than its more famous supermarket counterpart, but, at $10 a pound, it’s only a few bucks more. Cross my heart—the difference it makes in this cake is night and day.
But enough about that—let’s make a cake!
Texas sheet cake follows the rules of a classic butter cake, with the butter and sugar creamed together until fluffy and pale. (You can read more on the importance of creaming in my article on the subject.) Along the way, the bowl and beater should be thoroughly scraped to ensure the batter has a uniform texture; if dense areas are allowed to build up, they can create some weird, volcano-like pockets in the cake.
The creaming method can take a while, so in the meantime, start sifting the dry ingredients: all-purpose flour, natural cocoa, and malted milk powder (what I like to call the umami bomb of dessert).
Not only does sifting help homogenize the dry ingredients to reduce the amount of mixing required (and therefore reduce gluten development), it also helps remove any hardened lumps of cocoa that may not fully dissolve in the batter.
The malted milk powder is technically an optional ingredient, but it’s especially helpful in supplementing the flavor of low-quality cocoa powder, and it also works to add some malty, toffee-like notes that complement the fruitiness of the good stuff. It’s a win-win scenario if you have some on hand, but it won’t be the end of the world if you don’t.
Now, back to the butter and sugar. When the mixture is soft and light, add the eggs one by one, followed by the buttermilk* and dry ingredients in alternating additions. Going back and forth is the best way to preserve the air cells created by creaming. Adding the flour all at once will cause the air to be crushed out with the force it takes to incorporate such a huge volume of dry ingredients. Meanwhile, adding all the liquids at once will make the batter so soft and loose, it’ll no longer be effective at retaining air.
In many recipes, buttermilk substitutes can be a total crapshoot, but this recipe’s as gracious as a Southern belle; if buttermilk’s hard to find in your neck of the woods, use kefir as a 1:1 swap by weight or volume, or a 50/50 blend of milk and yogurt by weight.
To bake, grease a half-sheet pan and give it a light dusting of natural cocoa. This isn’t so much to help prevent sticking as it is to add a secondary layer of chocolate flavor to the cake’s bottom crust. Especially with a high-fat cocoa, this adds a velvety richness and aroma to every bite—like the cocoa dusting on chocolate truffles.
Fold the batter with a flexible spatula to make sure it’s well mixed from the bottom up, then scrape it into the prepared sheet pan and spread into an even layer with an offset spatula.
It pays to take your time at this stage, as uneven batter will cause the cake to bake into valleys and mountains, making it difficult to glaze. If one of those mountains happens to be near the edge of the pan, you may wind up with boiling-hot glaze pouring off the side and onto the floor. So take your time; there’s no rush.
While the cake’s in the oven, get started on the frosting by combining milk, sugar, butter, and natural cocoa in a two-quart stainless steel saucier. There isn't a ton of technique here; just whisk and boil till the mixture hits 220°F (104°C), then stir in some vanilla extract. This should move along pretty fast, so if you find it taking too long, by all means, crank up the heat so you can pour the glaze over the cake as soon as it comes out of the oven.
Should the timing be a little off and you find the cake still has a ways to go, simply cover the frosting to keep it from cooling too fast. As long as it’s gooey and warm, the exact temperature isn’t a big deal.
Be sure to place the cake on a flat surface, and pour slowly to prevent any spills. If needed, nudge the glaze into place with a spoon or spatula. Just remember not to lick it when you’re done—that sucker will be hot!
Finally, cover the cake in toasted pecans. Some folks like to mix the pecans straight into the hot fudge, giving them a candy-coated quality, but I like to keep them separated. The glaze is easier to spread when it’s perfectly smooth, and the visual contrast between the two is something to behold.
I don’t get to say this about a lot of cakes, but this one is phenomenal when warm, so feel free to slice it on up!
Not that anything is lost as it cools; as noted above, combining hot cake with boiled fudge creates a major infusion of moisture that gives the cake a remarkable shelf life, so it's a great make-ahead dessert. Plus, the cooler the frosting, the more fudge-like it becomes.
The cake's low profile makes it easy to serve on paper plates or napkins, making it right at home on any picnic table, but its overall lightness means it's just as amenable to being served à la mode after dinner. It's a kind of versatility not many cakes can offer, so you may find yourself making it again and again.