1Preheat the oven to 200 degrees Celsius.
2Sift together the flour and cocoa powdered. Whisk in the sugar, baking powder and baking soda.
3Add the milk, water, and olive oil and mix until combined.
4Grease and flour 2 circular cake pans and divide the batter into each.
5Bake 35 to 40 minutes. Let cool on a rack and once cool, unmold.
6While the cake cools, make the frosting. Set a bowl over simmering water and add the egg whites. Whisk until frothy and add in the sugar little by little. The eggs will become voluminous and almost white in color.
7Scrape the beans out of the vanilla pod and beat them into the eggs.
8Then add the butter little by little until combined. Refrigerate the frosting 1 to 2 hours before use.
9Set 1 of the cooled cakes on a serving dish and top it with a generous amount of frosting.
10Add the 2nd cake on top of the 1st and top it with a generous amount of frosting too.
11Using an offset spatula, coat the sides and top of the cake with a very thin layer of frosting to set the crumbs. Scrape off excess frosting and refrigerate the cake 1 hour.
12After 1 hour, generously frost the sides and top.
13Place the remaining frosting in a pastry bag with a size 7 tip. Pipe rose blossom shapes on the top of the cake. Serve