The Secret Ingredient for Tender Cakes

Olive oil in the batter is the secret to a moist, tender cake with lots of character

Actually, I’m a fairly recent convert to the idea of olive oil cakes. After doing a bit of travelling through Spain, Portugal, and Greece, where olive oil reigns supreme -- even in desserts -- I returned home eager to see what goodies I might concoct with this golden liquid. After a few days in the kitchen, I came up with a troupe of unusual and terrific cakes that I find myself making again and again.

Curiosity compelled me to try these same cakes using a generic vegetable oil instead of olive oil. The results surprised me. The olive oil versions were moister and had a more tender, refined crumb (I’ve since learned that olive oil contains natural emulsifiers, which improve moisture and texture), but even more striking was their richer, deeper character. The olive oil seemed to act like an invisible helper, somehow coaxing superior savor and clarity from the ingredients, weaving them together to create a richer, more alive whole.

You must be thinking, don’t these cakes taste like olive oil?

No, they don’t -- nor would I want them to. Rather than use a high-end extra-virgin oil, I use the grade that’s simply called “olive oil” (this grade used to be called “pure” or “100-percent pure,” and some producers still label it that way). I prefer this oil for baking because it’s milder and cheaper than extra-virgin oil and because the flavor nuances that make the best extra-virgin olive oils so special would vanish in the heat of an oven anyway.

On the other hand, if you use extra-virgin olive oil as your everyday cooking oil, you can go ahead and use it in these cakes, too. I’ve used extra-virgin oil when it was the only kind available -- for a last-minute birthday cake made at my in-laws’ house -- and there was no olivy taste to the cake, although I could easily detect it in the sticky residue left in the pan. And just so you know, there were enough kids scarfing up the cake at this party that I’ve no doubt that one of them would have yelled, “Hey, this tastes funny..."

All three of these cakes have a lot going on flavorwise. The Carrot Cake with Orange Cream Cheese Frosting and the Dark Chocolate Cake are the two powerhouses, especially the chocolate cake, which is one delicious, meaty layer of super-chocolate cakehood. The most delicate of the bunch is the Plum & Blueberry Upside-Down Cake. It’s made with cake flour instead of all-purpose flour, which makes the cake magnificently tender.

Olive oil doesn’t help with leavening, but it does supply moistness. In cakes using butter and shortening, the fat is usually creamed with sugar to aerate the batter. But oil doesn’t hold air bubbles the way a solid fat will, so olive oil cakes get almost all their leavening from other sources, such as a chemical leaven like baking soda, or whipped egg whites (although when eggs and olive oil are whipped together in the chocolate cake, the combination does incorporate some air). Where oil outperforms butter is in its ability to coat flour proteins, which reduces gluten formation and keeps the crumb extra tender. The greased proteins can’t grab water to make gluten, and this means more unbound water is left in the cake, making it quite moist.

I’ve seen some recipes for oil-based cakes that call for blending everything together in a single bowl all at once. My cakes are simple to make, but I’m afraid they aren’t that simple. Here are a few points to keep in mind when making each one.

To make the  chocolate cake, you whip eggs with olive oil and sugar, mix in a chocolate paste made from cocoa powder and boiling water, and stir in flour. There are two keys to making this cake just right. First, whip the egg mixture until it’s thick and lemon colored -- the incorporated air from this process adds leavening power (the only other leavener is a smidgen of baking soda). Second, be sure the chocolate paste is warm but not hot so it mixes in easily and smoothly but doesn’t cook the eggs.

To make the  carrot cake, you slowly stir the olive oil and sugar for several minutes to blend them well before adding half of the dry ingredients. Then you stir in the remaining dry ingredients alternating with the eggs, finally stirring in the carrots and pecans. Again, two keys to success: First, the carrots and nuts should be very finely chopped so they become a fully integrated part of the crumb. Second, the batter should sit for 15 minutes before it’s poured into the pan. This resting period lets the carrots flavor the batter and thin it somewhat as they continue to give off moisture. It also lets the gluten in the flour relax for a more tender result.

To make the  plum and blueberry upside-down cake, you whisk olive oil, buttermilk, and egg yolks together lightly and stir them into the dry ingredients, finishing by folding in a stiff egg-white meringue for rising power and an airy texture. How you incorporate the meringue is the key; it’s best done in two stages for a smooth, well-amalgamated batter. You’ll pour half of the cake batter on top of the meringue and gently mix them by hand with a thin-wire whisk (I use the whisk attachment from my electric mixer, the same one I used to make the meringue) so they become a solid color with no white lumps or streaks. Then you’ll repeat this process with the rest of the batter. Be sure to scrape the bottom of the bowl -- sneaky lumps of batter have been known to hide out there.

If you have your own favorite oil-based cake recipes, you can safely replace the vegetable oil with olive oil, bake the cake, and see what you think. Butter-based cakes aren’t as simply done, however. More than likely, they would require some rebalancing of the other ingredients.