How to Make It
Make the cake Preheat the oven to 350°. Butter four 8-inch round cake pans and line them with parchment paper. Butter the paper and dust the pans with cocoa powder.
In a large bowl, whisk the flour with the granulated sugar, baking soda, baking powder, cinnamon, salt and 1 1/2 cups of cocoa powder. In a stand mixer fitted with the whisk, beat the eggs at medium speed until smooth, about 2 minutes. Add the buttermilk, olive oil, vanilla, orange blossom water and 1 1/4 cups warm water and beat at medium-low speed until incorporated, about 2 minutes. Gradually add the dry ingredients and whisk at medium speed until combined, about 1 minute. Divide the batter between the prepared pans.
Bake the cakes for about 35 minutes, until raised and a toothpick inserted in the centers comes out clean; rotate the cakes halfway through baking. Transfer the cakes to a wire rack to cool for 15 minutes. Turn them out onto the rack; peel off the parchment paper and let cool completely, about 1 hour.
Meanwhile, make the Swiss meringue In the bowl of a stand mixer set over a small saucepan with 2 inches of simmering water, whisk the superfine sugar with the egg whites and corn syrup until doubled in volume and the sugar is completely dissolved, about 5 minutes. Carefully transfer the bowl to a stand mixer fitted with the whisk and beat at medium-high speed until tripled in volume and stiff peaks form, about 5 minutes. Fold in the orange blossom water.
Set one cake layer flat side up on a cake stand. Using the back of a spoon, spread 1/2 cup of the meringue over the top, leaving the side of the cake unfrosted. Repeat with two more cake layers, spreading each with 1/2 cup of the meringue and leaving the sides unfrosted. Set the remaining cake layer on top. Vertically insert three 10-inch wooden dowels into the top of the cake to hold the layers in place. Garnish the top with dollops of the remaining meringue, edible flowers and fruit. Cut into wedges and serve, removing the dowels as you go.