In the bowl, combine flour and chopped hazelnuts. Set aside.
In the bowl of a stand mixer, beat the egg whites and granulated sugar until stiff peaks form. Using my Kitchen Aid mixer, it took me about 7 minutes.
Gently fold in the hazelnut mixture into egg whites.
Trace 8- or 9-inch circles on a sheet of parchment paper.
Split the hazelnut meringue between the two circles. Try to spread within the lines. This recipe makes four 8-inch circles. I bake two trays at a time.
Bake at 220oF (105oC) 2 hours.
Turn off the oven and let cool completely in the oven. Do not open the oven door while baking.
How to Make Chocolate Whipped Cream
In the small saucepan, warm up heavy cream.
Pour hot cream over chocolate an let set for a minute.
Mix with a whisk. Add cognac and mix again. You can also emulsify ganache with a blender (optional).
Transfer the ganache into a flat container and cover it with plastic wrap “to contact.” Let the ganache set in the refrigerator for 3-4 hours.
When you are ready to assemble the cake, whip chocolate ganache with a hand blender.
How to Make Cream Charlotte
In the mixing bowl, whisk egg yolks with half of the sugar and set aside.
In the medium saucepan, add milk and remaining sugar and warm up over medium heat. Do not boil!
Gradually, while whisking constantly, add hot milk to egg yolks.
When all is incorporated, pour the mixture back into the saucepan. Continue whisking, and cook until the mixture is thick and pudding consistency.
Transfer cream to a medium bowl. Cover with plastic wrap “to contact” and let cool in the refrigerator.
When you are ready to assemble cake, whip room temperature unsalted butter.
Add custard cream a few spoons at a time and keep whisking. The cream should be smooth and soft. Important: cream and butter should be at room temperature.
How to Assemble Kyiv Cake
Put the white cream on the first cake layer and smooth it out with the spatula. Cover with the second cake layer.
Add whipped ganache and cover with the third meringue layer.
Put cream Charlotte and final meringue layer.
Apply chocolate ganache on top and the sides of the cake.
Coat sides with the chopped hazelnuts.
Decorate the cake with the remaining ganache and cream Charlotte.
Refrigerate cake for 4- 6 hours or overnight. Before serving, get the cake out of the fridge 20 minutes in advance.
Notes
Measure all ingredients correctly using a kitchen digital scale.