Olive Oil Pudding Cake with Berries – Fustini's Oils & Vinegars

Ingredients

• 1 tablespoon unsalted butter
• 2/3 cup superfine sugar, plus more for dusting
• 2 eggs, separated
• 2/3 cup reduced-fat buttermilk
• 2 tablespoons Fustini’s Meyer Lemon olive oil
• 2 tablespoons lemon juice
• 1 tablespoon lemon zest
• 1/4 cup all-purpose flour
• 1/4 teaspoon salt
• 1 cup fresh raspberries
• 1 cup fresh blueberries
• 1 cup fresh blackberries
• 2 tablespoons confectioners' sugar