2 1/4 cups flour
3/4 cup instant polenta or yellow cornmeal
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1 teaspoon salt
1 1/2 cups sugar
4 large eggs
Zest from 3 large Meyer lemons (or 4 large regular lemons)
1 cup extra-virgin olive oil
1/4 cup freshly squeezed lemon juice
8 ounces fresh blackberries
Powdered sugar for dusting
Preheat the oven to 350F degrees. Spray an 10-inch springform pan with non-stick baking spray - or - spray a 10-inch round baking pan with baking spray and line it with parchment paper.
In a medium bowl, whisk together the flour, polenta, baking powder, baking soda, and salt.
In the bowl of an electric mixer fitted with the whisk attachment, beat the sugar and the eggs on medium-high speed for 4-5 minutes, until the mixture is pale yellow and tripled in volume. Mix in the lemon zest.
In a small bowl, whisk together the olive oil and the lemon juice. Add this to the egg mixture, alternating with the flour mixture, in two additions each, mixing after each addition until the ingredients are incorporated. Gently fold the blackberries into the batter.
Transfer the batter to the prepared pan, smoothing the top with a spatula. Bake the cake until the top springs back when lightly touched, and a cake tested inserted into the center emerges clean, 30-35 minutes.
Cool the cake in the pan set on a wire rack for 10 minutes, then release the sides of the pan and allow the cake to cool completely.
Sprinkle the cake with powdered sugar and garnish with additional fresh blackberries (optional) before serving.