Beat the egg whites and citric acid until fluffy, then gradually add 200 g of sugar, mixed baking powder, cornstarch, and flour. Continue beating until you have a stiff cream. Pour the mixture into a pan and bake in a preheated oven at 170°C (340°F).
In a separate bowl, beat the egg whites and salt, then gradually add 100 g of sugar, lemon juice, and lemon zest. Cook the mixture in a double boiler until you get a smooth paste, then let it cool. Beat the Cremio cooking cream, mix it into the lemon cream, and pour it over the baked cake layer. Let the lemon pie set in the refrigerator for a few hours.