Mix and combine chocolate, almonds, corn starch, baking powder and lemon zest.
Add lemon juice and melted butter, mix and combine.
With a handheld mixer whisk eggs and sugar for about 5 min until pale yellow and fluffy.
Gradually add and combine the eggs and sugar mixture with the dry ingredients.
Line a 23 cm cake tin with parchment paper, pour in the cake mixture and bake in the preheated oven at 170°C for 40 minutes. It is done when a toothpick inserted in the middle comes out clean. Leave the cake to cool slightly in a turned off an closed oven for 30 minutes.
After that time take the cake out of the cake tin, cool completely and, if you wish, dust it with icing sugar.