Preheat the oven to 350°F/180°C.
Cut 2 9-in. circles of parchment paper and line the bottom of 2 nonstick 9x2-in. round cake pans.
In a large bowl, mix the flours, sugar, baking powder and salt together.
Add the olive oil, zest, juice, vanilla and egg yolks.
In the bowl of a standing mixer, beat the egg whites at high speed until stiff peaks form.
Gently fold in the egg whites 1/3 at a time into the prepared batter. Gently pour the batter into the pans.
Bake for 25 - 30 minutes. (The cake is done when the top springs back when lightly touched.)
While cake is baking, prepare the Mojito lime garnish and faux crème fraiche.
Mix the berries, mint, zest and juice together in a bowl, mashing slightly with the bowl of a spoon. Set aside for at 30 minutes or until the berries have begun giving off juice.
Mix all crème fraiche ingredients together in a small bowl and refrigerate until ready to use.
When cakes are done baking, place on a nonstick 12x17-in. cooling rack until cool; run a knife around the sides of the cake and remove.
Top one cooled cake with the faux crème fraiche and Mojito lime garnish and sift the powdered sugar over the cake before serving.
Wrap the other with aluminum foil or freezer wrap, and place in the freezer for up to 60 days.