
Pre-heat oven to 340F (170C), lightly grease and flour or spray one 8 inch (20cm) round springform cake pan or regular pan.
In a medium bowl sift the flour, salt and baking powder.
In the bowl of a stand mixer with the whisk attachment beat the egg whites until stiff. Set aside.
In a separate large bowl beat the egg yolks and sugar for 15 minutes, add the vanilla, then add the flour a little at a time and beat to combine between each addition, add the hot water and beat to combine. Gently fold in the egg whites.
Transfer the batter to the prepared pan and bake for approximately 30-40 minutes or until a toothpick comes out clean or with a few crumbs attached. Leave in the pan to cool 15-20 minutes, then move to a wire rack to cool completely. When cool cut the cake into three layers.
While the cake cools, beat together the sugar and eggs* until frothy, then add the mascarpone and cream, beat until thick.
If you don't add the egg then beat together the powdered sugar, mascarpone and cream until thick.
Place 1 layer of cake (sliced side up) on a large plate and spoon 1/3 of the coffee on top, cover with 1/3 of the cream mixture and repeat with the remaining layers. Frost the cake with the remaining cream filling. Chill for 3-4 hours or even overnight. Bring to room temperature for 30 minute before serving. Sprinkle with unsweetened cocoa or sprinkle with chocolate flakes or chips and serve. Enjoy!
*For the replacement of raw eggs, you can try using a product called Egg Replacer or there are now pasteurized eggs available. Or you can leave it out completely, if you do then substitute powdered/icing sugar for granulated sugar.