Polish Chocolate & Walnut Cake

Steps

1. Preheat your oven to 170°C (150°C fan) or gas mark 3½. Prepare a 30 x 22cm shallow baking pan by lining it with baking parchment. Sift together 150g plain flour and 50g cocoa powder, then set this mixture aside.
2. In a mixing bowl, whisk 5 egg whites until stiff peaks form. Gradually add 200g caster sugar, mixing well until fully incorporated. Then, add 3 egg yolks one at a time, whisking continuously. Gently fold in the flour and cocoa mixture using a spatula. Pour the batter into the lined tin and bake for approximately 35 minutes. After baking, let it cool for 5 minutes before removing from the pan and re-lining the tin.
3. For the meringue, whisk remaining egg whites until stiff, then slowly add 200g caster sugar, one tablespoon at a time, until you achieve a stiff and shiny meringue. Fold in 250g finely chopped walnuts, 1 tablespoon plain flour, and 1 tablespoon potato starch. Spread this mixture into the re-lined tin and bake for another 40 minutes.
4. To prepare the chocolate glaze, gently heat 100g double cream in a saucepan. Remove from the heat and add 100g chocolate chips, stirring until melted and smooth.
5. Once both the chocolate sponge and meringue have cooled, slice each into two layers. Place the walnut meringue atop the first layer of sponge, sprinkle with reserved walnuts, then add another layer of meringue followed by the top layer of sponge. Pour the chocolate glaze over the top and decorate with walnuts. Refrigerate the completed cake for 1-2 hours before serving.