Cake filled with cream and topped with chocolate

Directions

1. For the cake:
   Preheat the oven to 180ºC (350ºF). Grease a round cake pan (25 x 6 centimeters (9 3/4 x 2 1/3 inches)) with margarine and sprinkle with flour.
2. Separate the yolks from the whites. Beat the egg whites until stiff peaks form and store in the fridge.
3. In an electric mixer, beat on medium speed the egg yolks together with the sugar and the lemon zest until obtain a creamy mixture. Add the softened margarine, milk and the liquid caramel and beat for 2 to 3 minutes to incorporate. Reduce the mixer speed to low, add the flour mixed with the baking powder and beat until obtain a homogeneous and creamy mixture. Finally, fold gently with a spatula the whipped egg whites.
4. Pour the mixture into the prepared pan and bake until a toothpick inserted in the center comes out clean, about 30 minutes (the time depends on the oven). Remove the cake from the oven, unmold and allow to cool completely.
5. For the filling:
   In a bowl, whisk well the egg yolks and the whole egg; set aside.
6. Pour the milk, sugar, lemon peel and the cinnamon stick in a saucepan and bring to a boil over medium-high heat. When starts boiling, reduce to low heat and cook for about 2 to 3 minutes. Turn off the heat and allow to cool slightly.
7. Then, add the eggs mixture and stir well. Place back the saucepan over low heat and stir with a wire whisk until obtain a very creamy mixture (pass a wooden spoon in the bottom of the saucepan and if it leaves a trail like a road, the sweet is ready). Turn off the heat, remove the cinnamon stick and the lemon peel and set aside.
8. For the topping:
   Place the chocolate broken into pieces in a bowl and melt in the microwave.
9. In an electric mixer, beat on medium speed the powdered sugar and the softened margarine until obtain a creamy and homogeneous texture. Add the melted chocolate, without stop beating.
10. Slice the cake in half with a long sharp knife. Place the bottom slice of the cake on a platter and spread with the cream. Cover with the top slice of the cake and spread with the chocolate. Sprinkle with powdered sugar and serve.