I found this recipe on a German site and I adapted to my taste. The result is a soft moist walnut cake with orange flavor and an attractive chocolate topping.
The quantities correspond to a big rectangular cake (serves 20-24 persons) or two 9 inch round cakes.
o 225 g butter (1 cup)
o 250 g sugar (1 cup + 2 tablespoons)
o 1 orange, only zest grated
o 7 egg yolks
o 100 g plain Greek yogurt (6 tablespoons)
o 225 g plain flour (1 3/4 cups)
o 2 teaspoon baking powder
o 2 teaspoons vanilla powder
o 7 egg whites
o 150 g powdered sugar (1 1/2 cups)
o 2 teaspoons lemon juice
o 2 tablespoon cornstarch
o 200 walnuts, peeled and roughly chopped (1 1/2 cups)
o 200 g dark chocolate, roughly chopped (1 1/2 cups)
- Preheat the oven to 200°C/400°F
- Mix butter with sugar until soft.
- Add orange zest and while beating one by one the egg yolks.
- Add yogurt, mix well again.
- Sieve in a bowl flour, baking powder and vanilla. Add this mixture to the creamy mixture.
- Spread the dough with a spatula in the cake form.
- In a fat free clean bowl beat egg whites until stiff.
- Slowly incorporate the powdered sugar in portions and mix until thick.
- Add lemon juice and cornstarch. Mix until well incorporated.
- Add walnuts and 100 g chopped chocolate. Fold under the mousse.
- Spread the mousse over the dough base.
- Reduce the heat of the oven at 180°C/350°F and bake for 30-35 minutes or until through (tooth stick test).
- Let cool dry on a grid.
- Place the remaining chocolate in a small plastic bag and make a knot.
- Place the bag in a bowl of hot water keeping the knot out of the water.
- When the chocolate is melted take out the bag. Knead the bag lightly with your fingers until you are sure the whole chocolate is melted. Cut an edge of the bag and drizzle the chocolate over the cake.