Preheat oven to 350°F Line the bottom of a 8- or 9-inch spring-form pan with parchment paper, then coat the entire pan with cooking spray.
Combine the almond flour, corn flour, and 1/3 cup of the sugar in a bowl.
Whisk the egg yolks and 1/3 cup of the sugar in another bowl with an electric mixer for 5 minutes. Beat in the lemon zest, oil, lemon juice, and orange juice. Fold in dry ingredients.
In a separate, clean bowl, beat the egg whites and salt until frothy. Add the last 1/3 c sugar and beat until stuff peaks form. Fold 1/3 of the egg white mixture into the batter. Fold in the remaining egg white mixture in two parts, mixing well.
Pour batter into the prepared pan. Bake 30-35 minutes. Remove from oven and allow to cool.
Invert pan, remove parchment, then turn cake right-side-up onto a plate. Garnish with berries and powdered sugar.