Chocolate and olive oil might seem an unlikely pair, but in the Mediterranean, they are soul mates. And while the combination shows up in numerous desserts—from cookies to gelato—nowhere is this affinity more apparent than in the deliciously moist olive oil-based chocolate cakes made across Spain, Italy and Greece.

It’s all part of a larger tradition dating to ancient times, when the region’s bakers used olive oil rather than the butter favored in Northern Europe. It was a matter of practicality: In the warm climate of the Mediterranean, olives and their oil were plentiful, while butter spoiled quickly without refrigeration.

But there was another benefit, too. Olive oil happens to produce particularly luscious—and flavorful—chocolate cakes.

Of all the ingredients that go into a cake, fat is one of the most important. Fat coats flour, which limits gluten formation to help cakes bake up fluffy, not chewy. Oil is particularly good at this, creating a plusher mouthfeel and softer crumb than butter because it is liquid at room temperature. Butter solidifies as it cools, resulting in a tougher texture.

We loved the rich, brownie-like quality that olive oil lends to chocolate cake. And while the fruity, peppery notes of extra-virgin olive oil can be a marvelous foil for chocolate, we found that light olive oil—which has a far more subtle flavor—also worked beautifully.

As for the chocolate, we doubled down by using both bittersweet chocolate and cocoa powder. And we found we could enhance those flavors even further with two of chocolate’s other surprising bedfellows: espresso and lemon. We often use espresso powder to amplify chocolate, as its roasty depth underscores the chocolate’s pleasant astringency. And it turns out that lemon juice balances both with a shot of citrusy brightness. Additionally, the acidity of the juice adds a bit of lift by reacting with the baking soda.

The finished chocolate olive oil cake is as deeply decadent as it is simple to make—and what’s not to love about that?