• To make the cake
• Preheat the oven to 180 C / 350 F. Butter and flour a 8 inch square pan , line the bottom with parchment.
• Separate the eggs .
• Whisk together the flour and baking powder in a bowl, keep aside.
• Beat the whites using an electric mixer or whisk until stiff peaks form. This takes 2-3 minutes.
• Add the yolks little by little while continuing beating.
• Once the yolks are incorporated , add the sugar one tablespoon at a time while continuing beating.
• Beat for a minute or two after the last of the sugar is added.
• Beat in the vanilla
• Sift in the flour- baking powder mixture on top of the batter.
• Using a spatula, gently fold in the flour until you can't see flour anymore .
• Immediately pour batter into prepared pan and smooth the top.
• Bake at 180 C / 350 F for 25- 30 minutes until the cake springs back when touched and the edges are coming away from the pan sides.
• Cool in pan for 10 minutes . Remove and cool completely on wire rack.

To make the orange curd

• In a thick bottomed saucepan, rub the orange zest into the white sugar. This will release some colour and flavour from the zest.
• Stir in the orange juice and eggs
• Cut the butter into small pieces and add to saucepan.
• Over medium heat, continuously whisk until butter has melted.
• Lower the heat and again stirring continuously cook until curd thickens . If you dip a spoon into the curd, the Curd should thickly coat the back of spoon and if u run a finger on it, there should be a clean trial on the spoon with intact curd on both sides of ur finger.
• Cover with plastic wrap touching the surface of the curd and cool in the fridge for atleast 4 hours.
• To make the dark chocolate ganache;
• Chop the chocolate as small and as evenly as possible. Place in a small bowl.
• Heat the cream in a saucepan or the microwave until it bubbles along the sides.
• Pour the hot cream over the chocolate. Cover and keep aside for a couple of minutes.
• Stir with a spatula until the chocolate has melted and you have smooth shiny ganache!
• Cover and rest for a few hours or overnight at room temperature.

To make the syrup

• In a saucepan, heat the juice, water and sugar.
• Bring to a boil and then simmer for few minutes.
• Take off heat and cool to room temperature.

To assemble

• Slice the chilled cake horizontally into two.
• Placing both slices on top of each other, Divide the cake in the middle. You will now have four slices of cake, each 8 inches x 4 inches.
• Place one slice over your serving plate. Using a brush or teaspoon, soak generously with syrup. You can use a little less than a quarter cup. Spread half of the orange curd.
• Place the second layer on top. Press gently, soak and spread half of the ganache. Repeat with third and fourth layer, spreading the remaining curd and ganache on top respectively.
• Smooth the ganache on top.
• Chill. After couple of hours or chilling or before serving, cut off a thin edge on all four sides to get neat sides.
• Slice and serve