Rosemary Olive Oil Cake
Makes one 9-inch (23cm) cake
1 cup (200g) sugar
2 tablespoons fresh rosemary
1 3/4 cups (225g) all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
3/4 cup (175ml) fruity olive oil
1/4 cup (55g) unsalted butter, melted and cooled
1 teaspoon finely grated lemon zest
4 large eggs, at room temperature
1 cup (240ml) whole-milk kefir or buttermilk, at room temperature
2 tablespoons confectioner’s sugar (optional)
Position a rack in the center of the oven and preheat to 350ºF (180ºC/gas mark 4). Butter a 9-inch (23cm) cake pan at least 2-inches (5cm) tall, line it with parchment paper, and butter that too. Dust the pan and paper with flour.
Combine the sugar, rosemary, and lemon zest in the bowl of a food processor fitted with a steel blade or in a mortar. Pulse or grind the sugar and rosemary until the leaves are finely ground and the sugar is fragrant.
Whisk the flour, baking powder, baking soda, and salt together in a medium bowl.
In a separate bowl, whisk the rosemary sugar olive oil, and melted butter, together. Add the eggs and whisk for 30 more seconds. Whisk in the kefir, then use a rubber spatula to fold in the dry ingredients, mixing until combined and smooth.
Pour the batter into the prepared pan, tap it gently on the counter to release any air bubbles, and bake until the cake is puffed and golden and a cake tester inserted into the center comes out clean, 40 to 45 minutes. Cool the cake in the pan on a rack for 20 minutes, then remove the cake from the pan to cool completely. Dust the cooled cake with a bit of confectioners’ sugar just before serving if you like. This cake will keep in an airtight container at room temperature for up to 4 days.