• Preheat the oven to 180°C (350°F). Slightly grease an 8x8 inch (20x20cm) square pan and line with parchment paper. Line it up in such a way that some edges overhang to make it easy to lift it up once it's set.

To make the crust

• In a large bowl, cream together butter and sugar until creamy. Add ground walnuts, orange zest, and flour. Mix well.
• Separate egg yolks from egg whites. Whip egg whites with salt until foamy. Gradually add 2 tablespoon of sugar and whip until stiff peaks. Fold in egg whites into walnut mixture.
• Pour the batter into prepared pan and bake for 15 minutes.

To make the orange layer

• Mix egg yolks with sugar and orange zest until thick and creamy.
• Remove the crust from the oven and add yolks mixture on top of the cake and bake for another 10-15 minutes. Let it cool slightly.

To make the chcolate ganache

• Heat the cream in a small saucepan. When the cream just begins to boil at the edges, remove from heat and pour over the chopped chocolate. Let sit one minute, then stir until smooth.
• Spread the chocolate ganache on top of the cake. Let it set before cutting the bars and serving.
• Enjoy!:)