Viennese Cake

Preheat oven to 350°F (175°C). Line a round cake pan with parchment paper and lightly butter the sides.

Crush graham crackers into fine crumbs using a food processor or by placing them in a sealed bag and crushing with a rolling pin until you have fine crumbs.

Whisk together the 8 egg yolks, 1 whole egg, and fine sugar in a large bowl over a warm water bath, beating constantly until the mixture is pale, thick, and reaches approximately 160°F (71°C) for food safety, about 8-10 minutes.

Remove the bowl from the water bath and continue whisking until the mixture cools slightly and forms a ribbon when the whisk is lifted.

Sift together cocoa powder, pastry flour, graham cracker crumbs, and ground almonds in a separate bowl to remove lumps and distribute ingredients evenly.

Gently fold the dry mixture into the egg yolk mixture in batches using a spatula, being careful not to deflate the batter.

In a clean, grease-free bowl, whip the 8 egg whites to stiff peaks, then add 1 tablespoon of water and whip until stiff and glossy.

Carefully fold the egg white mixture into the batter in two additions, maintaining the airiness of the meringue.

Pour the batter into the prepared pan and smooth the top with a spatula.

Bake in the preheated oven for 35 minutes, until a skewer inserted into the center comes out clean or with just a few moist crumbs.

Allow the cake to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.

Dust the top of the cooled cake generously with icing sugar before serving.