I don't think you can ever have too many recipes for chocolate cake, whether that's a Texas sheet cake made from natural cocoa or a double-dark devil's food made with both Dutch cocoa and a chocolate bar. There's a place for both in my heart, along with every style in between—including this supremely dark chocolate cake.
It contains a few "secret" ingredients—namely, extra-virgin olive oil and whole wheat flour. I know those must sound like alarmingly health-conscious choices for chocolate cake, but these ingredients are here for flavor alone; any dietary benefits are just a bonus.
This cake is a streamlined version of my aforementioned devil's food cake. While that recipe can be mixed up by hand in a single bowl, it requires heat to melt the dark chocolate and butter.
It's not a big deal, since I melt both in a big pot on the stove that then doubles as a mixing bowl. But switching to a nondairy formula and using Dutch cocoa powder alone make for an even easier technique.
Simplifying the ingredients simplifies the cake's flavor, too, eliminating the complexity that comes from a secondary source of chocolate, as well as the dairy solids in butter, which develop flavor as they bake and brown.
That's where those secret ingredients come in. Olive oil provides some of the fruitiness and astringency normally found in a good bar of dark chocolate, while whole wheat flour adds a subtle graham-like flavor to stand in for the toastiness of brown butter.
The result is a different sort of chocolate cake, to be sure, but one that still tastes classic overall, with a satisfying richness and depth.
Those who want a more traditional chocolate cake should stick to mild olive oils with a buttery profile, or the cheaper brands that a connoisseur would consider bland. They'll still have enough character to give the cake depth, but not enough to be distracting.
If, on the other hand, you're intrigued by the idea of a bolder olive oil presence, pick an oil that you love already, something sharp and peppery. Because the internal temperature of the cake will crest around a mere 200°F (93°C), the olive oil will retain much of its character in the finished cake. For more information, see our guide to olive oil.
Aside from nixing the chocolate bar and switching to olive oil and whole wheat flour, the cake differs from my devil's food by using whole eggs only, rather than a blend of whole eggs and yolks. The remaining ingredients—Dutch cocoa, brown sugar, baking soda, salt, black coffee, and vanilla—are the same, although the proportions have been slightly tweaked.
It's a perfect recipe for bakers who need to steer clear of dairy—or those who have found themselves suddenly fresh out of butter—as well as anyone looking to incorporate more whole wheat into their baking repertoire. It's also easy (and forgiving) enough for kids, should you have any desire to bring a little helper into the kitchen.
Start by whisking the brown sugar and Dutch cocoa together, along with the baking soda and salt, until well combined.
It's not necessary to eliminate every last lump of brown sugar, but it is important for the salt and baking soda to be well distributed up front.
Next, add the eggs, vanilla, olive oil, and coffee all at once.
Keep whisking until the batter is smooth, thick, and well emulsified, with no streaks of oil or egg white rising to the top.
Finally, add the whole wheat flour and whisk until it's well combined, with no pockets of unmixed flour lurking about.
Scrape the bowl with a flexible spatula, making sure to incorporate any bits of flour around the side, then pour the batter into a lightly greased and parchment-lined eight- by three-inch anodized aluminum cake pan.
It'll do just fine in an eight- by two-inch pan as well, if that's what you have on hand. The reduced height will lead to more doming, and, while that can be a problem for layer cakes, it's not a big deal in a single-layer snack cake.
Bake until the cake is puffed and firm to the touch, but still soft enough to retain an impression from being poked.
Let the cake cool completely in the pan, then loosen the edges with a butter knife and invert onto a plate, wire rack, or just the palm of your hand. After removing the cake from the pan, peel off the parchment and re-invert the cake onto a serving platter or cake stand so that it's right side up.
For a pop of contrast and a hint of sweetness, finish the cake with a dusting of powdered sugar. If you're feeling fancy, torn strips of parchment or even a wire rack can be placed over the cake as a simple stencil before you start dusting.
If powdered sugar isn't normally your jam, consider switching to an organic, tapioca-based brand. Because it still contains a portion of its natural molasses content, this style tastes a little less sweet and a little more complex than traditional powdered sugar, with a less gritty consistency thanks to the tapioca starch. (For more info, read up on the differences between conventional and organic powdered sugar.)
Thanks to the grassy aroma of olive oil, this cake has a lighter profile that also pairs well with fresh fruit, especially citrus and red fruits, like raspberries or cherries. But all of these are optional touches; the cake has plenty of flavor and natural sweetness to stand all on its own.