Use a 28cm round tin for this cake, so it does not grow too high.
For the cake
8 egg yolks
3/4 cup (150g) sugar
1 cup (130g) cocoa powder
1 tablespoon instant coffee powder
2 teaspoons baking powder
pinch of bicarbonate of soda
1/2 cup walnuts, chopped
8 egg whites
1/4 cup (50g) sugar
For the vanilla and caramel cream
3 egg yolks
3 tablespoons sugar
3 tablespoons cornstarch
3 cups (750ml) warm milk
3 tablespoons (21g) plain powdered gelatine
500g dulce de leche (creamy caramel)
2 teaspoons vanilla essence
1 1/3 cups (335ml) cream, double
For the frosting
3 egg whites
3 tablespoons caster sugar
For the chocolate coating
200g couverture chocolate
2/3 cups (170ml) cream, double
For the chocolate decorations
150g white chocolate
150g dark chocolate
Beat egg yolks and ¾ cup sugar for about 15 minutes, until light and thick.
Sift together cocoa, instant coffee, baking powder and bicarbonate.
Fold in chopped walnuts.
Fold gently into egg mixture.
In another bowl, whisk egg whites and ¼ cup sugar until stiff.
Fold into mixture.
Pour the mixture into a 28cm round tin, greased on the sides and lined with nonstick baking paper at the base.
Bake in a cool oven for about 40 minutes or until cooked when tested with a skewer. Remove from the oven and cool over a wire rack.
Vanilla and caramel cream
Soak powdered gelatine in ½ cup of milk. Set aside for 10 minutes.
Place egg yolks, sugar and cornstarch inside a saucepan.
Stir in 3 cups of milk in a thin stream until well mixed.
Fold in soaked gelatine.
Cook over a medium heat, stirring constantly, until mixture thickens.
Remove from heat. Fold in dulce de leche (creamy caramel which can be obtained by cooking condensed milk until it is a rich caramel colour) and vanilla essence.
Cool completely outside the fridge, until gelatine is half set.
Whip cream until stiff and fold it into the caramel custard.
Beat egg whites and caster sugar until firm and fold gently into mixture.
Place cake in a 28cm round tin with a removable base.
Pour vanilla and caramel cream onto it and refrigerate overnight until well set.
Place cream inside a small saucepan and warm up over a low heat.
Stir in chopped chocolate, until completely melted.
Remove cake from fridge and tin and place it on a serving dish.
Pour coating over the cake in a thin stream, allowing it to spread over the cake without covering the sides completely.
Melt dark chocolate and white chocolate in two different double boilers.
Using small paper or nylon piping bags, pipe swirls, crisscrosses or web patterns of dark chocolate on nonstick baking paper sheets.
Repeat procedure with white chocolate.
Set aside and allow to set.
Remove chocolate decorations from paper sheets and top cake with them, arranging them as we desire.
Besides being delicious and looking spectacular, this birthday cake is cool and freshening, ideal for a spring or summer day.